81944015 has 16 divisors (see below), whose sum is σ = 100237440. Its totient is φ = 64294560.

The previous prime is 81943993. The next prime is 81944039. The reversal of 81944015 is 51044918.

It is not a de Polignac number, because 81944015 - 2⁸ = 81943759 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110516 + ... + 111254.

It is an arithmetic number, because the mean of its divisors is an integer number (6264840).

Almost surely, 2^81944015 is an apocalyptic number.

81944015 is a deficient number, since it is larger than the sum of its proper divisors (18293425).

81944015 is a wasteful number, since it uses less digits than its factorization.

81944015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 81944015 is about 9052.2933558298. The cubic root of 81944015 is about 434.3492537921.

The spelling of 81944015 in words is "eighty-one million, nine hundred forty-four thousand, fifteen".