81313413 has 4 divisors (see below), whose sum is σ = 108417888. Its totient is φ = 54208940.

The previous prime is 81313391. The next prime is 81313417. The reversal of 81313413 is 31431318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81313413 - 2⁵ = 81313381 is a prime.

It is a super-2 number, since 2×81313413² = 13223742267417138, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81313417) 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, 13552233 + ... + 13552238.

It is an arithmetic number, because the mean of its divisors is an integer number (27104472).

Almost surely, 2^81313413 is an apocalyptic number.

It is an amenable number.

81313413 is a deficient number, since it is larger than the sum of its proper divisors (27104475).

81313413 is a wasteful number, since it uses less digits than its factorization.

81313413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27104474.

The product of its digits is 864, while the sum is 24.

The square root of 81313413 is about 9017.3950229542. The cubic root of 81313413 is about 433.2322019751.

The spelling of 81313413 in words is "eighty-one million, three hundred thirteen thousand, four hundred thirteen".