81365333858 has 16 divisors (see below), whose sum is σ = 125112574944. Its totient is φ = 39662535840.

The previous prime is 81365333779. The next prime is 81365333909. The reversal of 81365333858 is 85833356318.

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, 230660 + ... + 464687.

It is an arithmetic number, because the mean of its divisors is an integer number (7819535934).

Almost surely, 2^81365333858 is an apocalyptic number.

81365333858 is a deficient number, since it is larger than the sum of its proper divisors (43747241086).

81365333858 is a wasteful number, since it uses less digits than its factorization.

81365333858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696817.

The product of its digits is 6220800, while the sum is 53.

The spelling of 81365333858 in words is "eighty-one billion, three hundred sixty-five million, three hundred thirty-three thousand, eight hundred fifty-eight".