861757556556 has 48 divisors (see below), whose sum is σ = 2166085380704. Its totient is φ = 265077398016.

The previous prime is 861757556551. The next prime is 861757556563. The reversal of 861757556556 is 655655757168.

It is a super-2 number, since 2×861757556556² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (861757556551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 292681 + ... + 1345056.

Almost surely, 2^861757556556 is an apocalyptic number.

It is an amenable number.

861757556556 is an abundant number, since it is smaller than the sum of its proper divisors (1304327824148).

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

861757556556 is a wasteful number, since it uses less digits than its factorization.

861757556556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1641130 (or 1641128 counting only the distinct ones).

The product of its digits is 264600000, while the sum is 66.

The spelling of 861757556556 in words is "eight hundred sixty-one billion, seven hundred fifty-seven million, five hundred fifty-six thousand, five hundred fifty-six".