665613597600 has 432 divisors, whose sum is σ = 2727899778240. Its totient is φ = 149560934400.

The previous prime is 665613597557. The next prime is 665613597611. The reversal of 665613597600 is 6795316566.

665613597600 is a `hidden beast` number, since 6 + 6 + 561 + 3 + 5 + 9 + 76 + 0 + 0 = 666.

It is a super-2 number, since 2×665613597600² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2861680 + ... + 3085520.

It is an arithmetic number, because the mean of its divisors is an integer number (6314582820).

Almost surely, 2^665613597600 is an apocalyptic number.

665613597600 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 665613597600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1363949889120).

665613597600 is an abundant number, since it is smaller than the sum of its proper divisors (2062286180640).

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

665613597600 is a wasteful number, since it uses less digits than its factorization.

665613597600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223933 (or 223917 counting only the distinct ones).

The product of its (nonzero) digits is 6123600, while the sum is 54.

The spelling of 665613597600 in words is "six hundred sixty-five billion, six hundred thirteen million, five hundred ninety-seven thousand, six hundred".