661136762304 has 224 divisors, whose sum is σ = 1985686656000. Its totient is φ = 215658713088.

The previous prime is 661136762303. The next prime is 661136762317. The reversal of 661136762304 is 403267631166.

661136762304 is a `hidden beast` number, since 6 + 6 + 1 + 13 + 6 + 7 + 623 + 0 + 4 = 666.

661136762304 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 661136762304.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661136762303) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15404427 + ... + 15447285.

Almost surely, 2^661136762304 is an apocalyptic number.

661136762304 is a gapful number since it is divisible by the number (64) 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 661136762304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (992843328000).

661136762304 is an abundant number, since it is smaller than the sum of its proper divisors (1324549893696).

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

661136762304 is a wasteful number, since it uses less digits than its factorization.

661136762304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43072 (or 43056 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The spelling of 661136762304 in words is "six hundred sixty-one billion, one hundred thirty-six million, seven hundred sixty-two thousand, three hundred four".