81031767855 has 32 divisors (see below), whose sum is σ = 131519531520. Its totient is φ = 42594437760.

The previous prime is 81031767799. The next prime is 81031767881. The reversal of 81031767855 is 55876713018.

It is not a de Polignac number, because 81031767855 - 2⁷ = 81031767727 is a prime.

It is a super-2 number, since 2×81031767855² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81031767798 and 81031767807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3837316 + ... + 3858374.

It is an arithmetic number, because the mean of its divisors is an integer number (4109985360).

Almost surely, 2^81031767855 is an apocalyptic number.

81031767855 is a deficient number, since it is larger than the sum of its proper divisors (50487763665).

81031767855 is a wasteful number, since it uses less digits than its factorization.

81031767855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24751.

The product of its (nonzero) digits is 1411200, while the sum is 51.

The spelling of 81031767855 in words is "eighty-one billion, thirty-one million, seven hundred sixty-seven thousand, eight hundred fifty-five".