661624974238896 has 240 divisors, whose sum is σ = 1870840629964800. Its totient is φ = 218262602460672.

The previous prime is 661624974238867. The next prime is 661624974238901. The reversal of 661624974238896 is 698832479426166.

661624974238896 is a `hidden beast` number, since 6 + 6 + 1 + 6 + 2 + 497 + 4 + 2 + 38 + 8 + 96 = 666.

It is a hoax number, since the sum of its digits (81) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28943729515 + ... + 28943752373.

It is an arithmetic number, because the mean of its divisors is an integer number (7795169291520).

Almost surely, 2^{661624974238896} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661624974238896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (935420314982400).

661624974238896 is an abundant number, since it is smaller than the sum of its proper divisors (1209215655725904).

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

661624974238896 is a wasteful number, since it uses less digits than its factorization.

661624974238896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26856 (or 26847 counting only the distinct ones).

The product of its digits is 9029615616, while the sum is 81.

The spelling of 661624974238896 in words is "six hundred sixty-one trillion, six hundred twenty-four billion, nine hundred seventy-four million, two hundred thirty-eight thousand, eight hundred ninety-six".