656389218690 has 24 divisors (see below), whose sum is σ = 1706611968828. Its totient is φ = 175037124960.

The previous prime is 656389218599. The next prime is 656389218691. The reversal of 656389218690 is 96812983656.

656389218690 is a `hidden beast` number, since 6 + 563 + 8 + 9 + 2 + 1 + 8 + 69 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 652697562609 + 3691656081 = 807897^2 + 60759^2 .

It is a super-2 number, since 2×656389218690² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (656389218691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3646606681 + ... + 3646606860.

Almost surely, 2^656389218690 is an apocalyptic number.

656389218690 is an abundant number, since it is smaller than the sum of its proper divisors (1050222750138).

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

656389218690 is a wasteful number, since it uses less digits than its factorization.

656389218690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7293213554 (or 7293213551 counting only the distinct ones).

The product of its (nonzero) digits is 33592320, while the sum is 63.

The spelling of 656389218690 in words is "six hundred fifty-six billion, three hundred eighty-nine million, two hundred eighteen thousand, six hundred ninety".