81682539 has 16 divisors (see below), whose sum is σ = 115342080. Its totient is φ = 51274080.

The previous prime is 81682507. The next prime is 81682543. The reversal of 81682539 is 93528618.

It is not a de Polignac number, because 81682539 - 2⁵ = 81682507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81682539.

It is not an unprimeable number, because it can be changed into a prime (81682339) 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, 5229 + ... + 13809.

It is an arithmetic number, because the mean of its divisors is an integer number (7208880).

Almost surely, 2^81682539 is an apocalyptic number.

81682539 is a deficient number, since it is larger than the sum of its proper divisors (33659541).

81682539 is a wasteful number, since it uses less digits than its factorization.

81682539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8770.

The product of its digits is 103680, while the sum is 42.

The square root of 81682539 is about 9037.8392882370. The cubic root of 81682539 is about 433.8867716964.

The spelling of 81682539 in words is "eighty-one million, six hundred eighty-two thousand, five hundred thirty-nine".