81085475 has 12 divisors (see below), whose sum is σ = 100878960. Its totient is φ = 64653600.

The previous prime is 81085471. The next prime is 81085489. The reversal of 81085475 is 57458018.

It is not a de Polignac number, because 81085475 - 2² = 81085471 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81085471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2561 + ... + 12989.

It is an arithmetic number, because the mean of its divisors is an integer number (8406580).

Almost surely, 2^81085475 is an apocalyptic number.

81085475 is a deficient number, since it is larger than the sum of its proper divisors (19793485).

81085475 is a wasteful number, since it uses less digits than its factorization.

81085475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10750 (or 10745 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 38.

The square root of 81085475 is about 9004.7473590323. The cubic root of 81085475 is about 432.8270105306.

The spelling of 81085475 in words is "eighty-one million, eighty-five thousand, four hundred seventy-five".