81392330 has 16 divisors (see below), whose sum is σ = 146905704. Its totient is φ = 32468160.

The previous prime is 81392321. The next prime is 81392359. The reversal of 81392330 is 3329318.

It can be written as a sum of positive squares in 4 ways, for example, as 69372241 + 12020089 = 8329^2 + 3467^2 .

It is a super-2 number, since 2×81392330² = 13249422765657800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81392293 and 81392302.

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, 7181 + ... + 14640.

Almost surely, 2^81392330 is an apocalyptic number.

81392330 is a deficient number, since it is larger than the sum of its proper divisors (65513374).

81392330 is a wasteful number, since it uses less digits than its factorization.

81392330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22201.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 81392330 is about 9021.7697820328. The cubic root of 81392330 is about 433.3723114182.

The spelling of 81392330 in words is "eighty-one million, three hundred ninety-two thousand, three hundred thirty".