81313093 has 12 divisors (see below), whose sum is σ = 84651264. Its totient is φ = 78101400.

The previous prime is 81313081. The next prime is 81313109. The reversal of 81313093 is 39031318.

It is a de Polignac number, because none of the positive numbers 2^k-81313093 is a prime.

It is a super-2 number, since 2×81313093² = 13223638186453298, which 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 (81313493) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 183330 + ... + 183772.

It is an arithmetic number, because the mean of its divisors is an integer number (7054272).

Almost surely, 2^81313093 is an apocalyptic number.

It is an amenable number.

81313093 is a deficient number, since it is larger than the sum of its proper divisors (3338171).

81313093 is a wasteful number, since it uses less digits than its factorization.

81313093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696 (or 665 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 81313093 is about 9017.3772794533. The cubic root of 81313093 is about 433.2316336618.

The spelling of 81313093 in words is "eighty-one million, three hundred thirteen thousand, ninety-three".