81372319 has 16 divisors (see below), whose sum is σ = 99864576. Its totient is φ = 64713600.

The previous prime is 81372311. The next prime is 81372349. The reversal of 81372319 is 91327318.

It is not a de Polignac number, because 81372319 - 2³ = 81372311 is a prime.

It is a super-2 number, since 2×81372319² = 13242908598875522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81372311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3634 + ... + 13264.

It is an arithmetic number, because the mean of its divisors is an integer number (6241536).

Almost surely, 2^81372319 is an apocalyptic number.

81372319 is a deficient number, since it is larger than the sum of its proper divisors (18492257).

81372319 is a wasteful number, since it uses less digits than its factorization.

81372319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9726.

The product of its digits is 9072, while the sum is 34.

The square root of 81372319 is about 9020.6606742522. The cubic root of 81372319 is about 433.3367924116.

The spelling of 81372319 in words is "eighty-one million, three hundred seventy-two thousand, three hundred nineteen".