81310986256 has 40 divisors (see below), whose sum is σ = 167491333440. Its totient is φ = 38154120576.

The previous prime is 81310986199. The next prime is 81310986293. The reversal of 81310986256 is 65268901318.

It is a super-2 number, since 2×81310986256² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2064966 + ... + 2103973.

It is an arithmetic number, because the mean of its divisors is an integer number (4187283336).

Almost surely, 2^81310986256 is an apocalyptic number.

It is an amenable number.

81310986256 is an abundant number, since it is smaller than the sum of its proper divisors (86180347184).

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

81310986256 is a wasteful number, since it uses less digits than its factorization.

81310986256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4169023 (or 4169017 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 49.

The spelling of 81310986256 in words is "eighty-one billion, three hundred ten million, nine hundred eighty-six thousand, two hundred fifty-six".