657363982640 has 80 divisors (see below), whose sum is σ = 1567310998176. Its totient is φ = 256272844800.

The previous prime is 657363982621. The next prime is 657363982657. The reversal of 657363982640 is 46289363756.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 657363982640.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1378580 + ... + 1793100.

Almost surely, 2^657363982640 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 657363982640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (783655499088).

657363982640 is an abundant number, since it is smaller than the sum of its proper divisors (909947015536).

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

657363982640 is a wasteful number, since it uses less digits than its factorization.

657363982640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415038 (or 415032 counting only the distinct ones).

The product of its (nonzero) digits is 39191040, while the sum is 59.

The spelling of 657363982640 in words is "six hundred fifty-seven billion, three hundred sixty-three million, nine hundred eighty-two thousand, six hundred forty".