81294915 has 24 divisors (see below), whose sum is σ = 140851440. Its totient is φ = 40020864.

The previous prime is 81294887. The next prime is 81294947. The reversal of 81294915 is 51949218.

It is not a de Polignac number, because 81294915 - 2¹² = 81290819 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13500 + ... + 18569.

It is an arithmetic number, because the mean of its divisors is an integer number (5868810).

Almost surely, 2^81294915 is an apocalyptic number.

81294915 is a deficient number, since it is larger than the sum of its proper divisors (59556525).

81294915 is a wasteful number, since it uses less digits than its factorization.

81294915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32103 (or 32090 counting only the distinct ones).

The product of its digits is 25920, while the sum is 39.

The square root of 81294915 is about 9016.3692803700. The cubic root of 81294915 is about 433.1993474650.

The spelling of 81294915 in words is "eighty-one million, two hundred ninety-four thousand, nine hundred fifteen".