861859244640 has 96 divisors (see below), whose sum is σ = 2714988852576. Its totient is φ = 229817937920.

The previous prime is 861859244629. The next prime is 861859244683. The reversal of 861859244640 is 46442958168.

It is a tau number, because it is divible by the number of its divisors (96).

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, 15780580 + ... + 15835100.

It is an arithmetic number, because the mean of its divisors is an integer number (28281133881).

Almost surely, 2^861859244640 is an apocalyptic number.

861859244640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

861859244640 is an abundant number, since it is smaller than the sum of its proper divisors (1853129607936).

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

861859244640 is a wasteful number, since it uses less digits than its factorization.

861859244640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87472 (or 87464 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 57.

The spelling of 861859244640 in words is "eight hundred sixty-one billion, eight hundred fifty-nine million, two hundred forty-four thousand, six hundred forty".