861592840942581 has 120 divisors (see below), whose sum is σ = 1390457616912000. Its totient is φ = 514003461048000.

The previous prime is 861592840942459. The next prime is 861592840942763. The reversal of 861592840942581 is 185249048295168.

861592840942581 is a `hidden beast` number, since 8 + 6 + 1 + 5 + 9 + 284 + 0 + 94 + 258 + 1 = 666.

It is not a de Polignac number, because 861592840942581 - 2⁷ = 861592840942453 is a prime.

It is a super-2 number, since 2×861592840942581² (a number of 31 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861592840942781) 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 119 ways as a sum of consecutive naturals, for example, 5903309995 + ... + 5903455943.

It is an arithmetic number, because the mean of its divisors is an integer number (11587146807600).

Almost surely, 2^{861592840942581} is an apocalyptic number.

It is an amenable number.

861592840942581 is a deficient number, since it is larger than the sum of its proper divisors (528864775969419).

861592840942581 is a wasteful number, since it uses less digits than its factorization.

861592840942581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146701 (or 146665 counting only the distinct ones).

The product of its (nonzero) digits is 398131200, while the sum is 72.

The spelling of 861592840942581 in words is "eight hundred sixty-one trillion, five hundred ninety-two billion, eight hundred forty million, nine hundred forty-two thousand, five hundred eighty-one".