656787680720 has 20 divisors (see below), whose sum is σ = 1527031357860. Its totient is φ = 262715072256.

The previous prime is 656787680719. The next prime is 656787680797. The reversal of 656787680720 is 27086787656.

656787680720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 235830669376 + 420957011344 = 485624^2 + 648812^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-3 number, since 3×656787680720³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4104922925 + ... + 4104923084.

It is an arithmetic number, because the mean of its divisors is an integer number (76351567893).

Almost surely, 2^656787680720 is an apocalyptic number.

It is an amenable number.

656787680720 is an abundant number, since it is smaller than the sum of its proper divisors (870243677140).

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

656787680720 is a wasteful number, since it uses less digits than its factorization.

656787680720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8209846022 (or 8209846016 counting only the distinct ones).

The product of its (nonzero) digits is 47416320, while the sum is 62.

The spelling of 656787680720 in words is "six hundred fifty-six billion, seven hundred eighty-seven million, six hundred eighty thousand, seven hundred twenty".