656990921039 has 8 divisors (see below), whose sum is σ = 699523691760. Its totient is φ = 614889955456.

The previous prime is 656990921033. The next prime is 656990921053. The reversal of 656990921039 is 930129099656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 656990921039 - 2⁸ = 656990920783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656990921033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107948144 + ... + 107954229.

It is an arithmetic number, because the mean of its divisors is an integer number (87440461470).

Almost surely, 2^656990921039 is an apocalyptic number.

656990921039 is a deficient number, since it is larger than the sum of its proper divisors (42532770721).

656990921039 is a wasteful number, since it uses less digits than its factorization.

656990921039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215902569.

The product of its (nonzero) digits is 7085880, while the sum is 59.

The spelling of 656990921039 in words is "six hundred fifty-six billion, nine hundred ninety million, nine hundred twenty-one thousand, thirty-nine".