81573315 has 16 divisors (see below), whose sum is σ = 130636800. Its totient is φ = 43465952.

The previous prime is 81573299. The next prime is 81573353. The reversal of 81573315 is 51337518.

It is a cyclic number.

It is not a de Polignac number, because 81573315 - 2⁴ = 81573299 is a prime.

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, 22606 + ... + 25964.

It is an arithmetic number, because the mean of its divisors is an integer number (8164800).

Almost surely, 2^81573315 is an apocalyptic number.

81573315 is a deficient number, since it is larger than the sum of its proper divisors (49063485).

81573315 is a wasteful number, since it uses less digits than its factorization.

81573315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4986.

The product of its digits is 12600, while the sum is 33.

The square root of 81573315 is about 9031.7946721568. The cubic root of 81573315 is about 433.6932909830.

The spelling of 81573315 in words is "eighty-one million, five hundred seventy-three thousand, three hundred fifteen".