1557681656 has 32 divisors (see below), whose sum is σ = 2986729200. Its totient is φ = 761368320.

The previous prime is 1557681637. The next prime is 1557681673. The reversal of 1557681656 is 6561867551.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 76316 + ... + 94548.

Almost surely, 2^1557681656 is an apocalyptic number.

It is an amenable number.

1557681656 is a deficient number, since it is larger than the sum of its proper divisors (1429047544).

1557681656 is a wasteful number, since it uses less digits than its factorization.

1557681656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18479 (or 18475 counting only the distinct ones).

The product of its digits is 1512000, while the sum is 50.

The square root of 1557681656 is about 39467.4759263878. The cubic root of 1557681656 is about 1159.2031923914.

The spelling of 1557681656 in words is "one billion, five hundred fifty-seven million, six hundred eighty-one thousand, six hundred fifty-six".