661594710712320 has 7056 divisors, whose sum is σ = 3157003828828584. Its totient is φ = 132434362368000.

The previous prime is 661594710712319. The next prime is 661594710712321. The reversal of 661594710712320 is 23217017495166.

661594710712320 is a `hidden beast` number, since 6 + 6 + 1 + 594 + 7 + 1 + 0 + 7 + 1 + 23 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (661594710712319) and next prime (661594710712321).

It can be written as a sum of positive squares in 4 ways, for example, as 659452538916864 + 2142171795456 = 25679808^2 + 1463616^2 .

It is a tau number, because it is divible by the number of its divisors (7056).

It is a super-2 number, since 2×661594710712320² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (661594710712321) by changing a digit.

It is a polite number, since it can be written in 503 ways as a sum of consecutive naturals, for example, 6550442680270 + ... + 6550442680370.

Almost surely, 2^{661594710712320} is an apocalyptic number.

661594710712320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661594710712320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1578501914414292).

661594710712320 is an abundant number, since it is smaller than the sum of its proper divisors (2495409118116264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661594710712320 is a wasteful number, since it uses less digits than its factorization.

661594710712320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 661594710712320 in words is "six hundred sixty-one trillion, five hundred ninety-four billion, seven hundred ten million, seven hundred twelve thousand, three hundred twenty".