861904951831 has 8 divisors (see below), whose sum is σ = 1074582797184. Its totient is φ = 671614248120.

The previous prime is 861904951813. The next prime is 861904951847. The reversal of 861904951831 is 138159409168.

It is a happy number.

861904951831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 861904951831 - 2²⁵ = 861871397399 is a prime.

It is a super-2 number, since 2×861904951831² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861904951931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5596785325 + ... + 5596785478.

It is an arithmetic number, because the mean of its divisors is an integer number (134322849648).

Almost surely, 2^861904951831 is an apocalyptic number.

861904951831 is a deficient number, since it is larger than the sum of its proper divisors (212677845353).

861904951831 is a wasteful number, since it uses less digits than its factorization.

861904951831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11193570821.

The product of its (nonzero) digits is 1866240, while the sum is 55.

The spelling of 861904951831 in words is "eight hundred sixty-one billion, nine hundred four million, nine hundred fifty-one thousand, eight hundred thirty-one".