81285595912 has 16 divisors (see below), whose sum is σ = 159037035840. Its totient is φ = 38875719696.

The previous prime is 81285595903. The next prime is 81285595913. The reversal of 81285595912 is 21959558218.

It is a super-2 number, since 2×81285595912² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81285595913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220884588 + ... + 220884955.

It is an arithmetic number, because the mean of its divisors is an integer number (9939814740).

Almost surely, 2^81285595912 is an apocalyptic number.

It is an amenable number.

81285595912 is a deficient number, since it is larger than the sum of its proper divisors (77751439928).

81285595912 is a wasteful number, since it uses less digits than its factorization.

81285595912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441769572 (or 441769568 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 55.

The spelling of 81285595912 in words is "eighty-one billion, two hundred eighty-five million, five hundred ninety-five thousand, nine hundred twelve".