81272475 has 18 divisors (see below), whose sum is σ = 145568436. Its totient is φ = 43345200.

The previous prime is 81272453. The next prime is 81272489. The reversal of 81272475 is 57427218.

It is not a de Polignac number, because 81272475 - 2¹⁸ = 81010331 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 180381 + ... + 180830.

Almost surely, 2^81272475 is an apocalyptic number.

81272475 is a deficient number, since it is larger than the sum of its proper divisors (64295961).

81272475 is a wasteful number, since it uses less digits than its factorization.

81272475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361227 (or 361219 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 81272475 is about 9015.1247911496. The cubic root of 81272475 is about 433.1594848326.

The spelling of 81272475 in words is "eighty-one million, two hundred seventy-two thousand, four hundred seventy-five".