81461575 has 24 divisors (see below), whose sum is σ = 111117888. Its totient is φ = 58865280.

The previous prime is 81461563. The next prime is 81461581. The reversal of 81461575 is 57516418.

It is not a de Polignac number, because 81461575 - 2⁵ = 81461543 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 12609 + ... + 17941.

It is an arithmetic number, because the mean of its divisors is an integer number (4629912).

Almost surely, 2^81461575 is an apocalyptic number.

81461575 is a deficient number, since it is larger than the sum of its proper divisors (29656313).

81461575 is a wasteful number, since it uses less digits than its factorization.

81461575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5403 (or 5398 counting only the distinct ones).

The product of its digits is 33600, while the sum is 37.

The square root of 81461575 is about 9025.6066278118. The cubic root of 81461575 is about 433.4951745908.

The spelling of 81461575 in words is "eighty-one million, four hundred sixty-one thousand, five hundred seventy-five".