861931165940 has 48 divisors (see below), whose sum is σ = 1968590448720. Its totient is φ = 315100492800.

The previous prime is 861931165939. The next prime is 861931165957. The reversal of 861931165940 is 49561139168.

It can be written as a sum of positive squares in 8 ways, for example, as 6772302436 + 855158863504 = 82294^2 + 924748^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16385225 + ... + 16437744.

It is an arithmetic number, because the mean of its divisors is an integer number (41012301015).

Almost surely, 2^861931165940 is an apocalyptic number.

It is an amenable number.

861931165940 is an abundant number, since it is smaller than the sum of its proper divisors (1106659282780).

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

861931165940 is a wasteful number, since it uses less digits than its factorization.

861931165940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32823092 (or 32823090 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 53.

The spelling of 861931165940 in words is "eight hundred sixty-one billion, nine hundred thirty-one million, one hundred sixty-five thousand, nine hundred forty".