81516339 has 6 divisors (see below), whose sum is σ = 117745836. Its totient is φ = 54344220.

The previous prime is 81516319. The next prime is 81516341. The reversal of 81516339 is 93361518.

It is a happy number.

81516339 is a `hidden beast` number, since 8 + 15 + 1 + 633 + 9 = 666.

It is not a de Polignac number, because 81516339 - 2²⁰ = 80467763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81516319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4528677 + ... + 4528694.

It is an arithmetic number, because the mean of its divisors is an integer number (19624306).

Almost surely, 2^81516339 is an apocalyptic number.

81516339 is a deficient number, since it is larger than the sum of its proper divisors (36229497).

81516339 is a wasteful number, since it uses less digits than its factorization.

81516339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9057377 (or 9057374 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 81516339 is about 9028.6399307980. The cubic root of 81516339 is about 433.5922944573.

The spelling of 81516339 in words is "eighty-one million, five hundred sixteen thousand, three hundred thirty-nine".