81156313 has 4 divisors (see below), whose sum is σ = 92750080. Its totient is φ = 69562548.

The previous prime is 81156287. The next prime is 81156319. The reversal of 81156313 is 31365118.

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 81156313 - 2⁹ = 81155801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81156319) 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, 5796873 + ... + 5796886.

It is an arithmetic number, because the mean of its divisors is an integer number (23187520).

Almost surely, 2^81156313 is an apocalyptic number.

It is an amenable number.

81156313 is a deficient number, since it is larger than the sum of its proper divisors (11593767).

81156313 is a wasteful number, since it uses less digits than its factorization.

81156313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11593766.

The product of its digits is 2160, while the sum is 28.

The square root of 81156313 is about 9008.6798699921. The cubic root of 81156313 is about 432.9530161460.

The spelling of 81156313 in words is "eighty-one million, one hundred fifty-six thousand, three hundred thirteen".