861704642618631 has 16 divisors (see below), whose sum is σ = 1458970823481600. Its totient is φ = 492402652924824.

The previous prime is 861704642618563. The next prime is 861704642618683. The reversal of 861704642618631 is 136816246407168.

861704642618631 is a `hidden beast` number, since 8 + 6 + 1 + 7 + 0 + 4 + 6 + 4 + 2 + 618 + 6 + 3 + 1 = 666.

It is not a de Polignac number, because 861704642618631 - 2¹¹ = 861704642616583 is a prime.

It is a super-2 number, since 2×861704642618631² (a number of 31 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861704642618531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2279641911501 + ... + 2279641911878.

It is an arithmetic number, because the mean of its divisors is an integer number (91185676467600).

Almost surely, 2^{861704642618631} is an apocalyptic number.

861704642618631 is a deficient number, since it is larger than the sum of its proper divisors (597266180862969).

861704642618631 is a wasteful number, since it uses less digits than its factorization.

861704642618631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4559283823395 (or 4559283823389 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 63.

The spelling of 861704642618631 in words is "eight hundred sixty-one trillion, seven hundred four billion, six hundred forty-two million, six hundred eighteen thousand, six hundred thirty-one".