81801315 has 24 divisors (see below), whose sum is σ = 146680560. Its totient is φ = 42122304.

The previous prime is 81801299. The next prime is 81801323. The reversal of 81801315 is 51310818.

It is not a de Polignac number, because 81801315 - 2⁴ = 81801299 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30037 + ... + 32646.

It is an arithmetic number, because the mean of its divisors is an integer number (6111690).

Almost surely, 2^81801315 is an apocalyptic number.

81801315 is a deficient number, since it is larger than the sum of its proper divisors (64879245).

81801315 is a wasteful number, since it uses less digits than its factorization.

81801315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62723 (or 62720 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 81801315 is about 9044.4079408218. The cubic root of 81801315 is about 434.0969772741.

The spelling of 81801315 in words is "eighty-one million, eight hundred one thousand, three hundred fifteen".