81375305 has 32 divisors (see below), whose sum is σ = 111231360. Its totient is φ = 56609280.

The previous prime is 81375289. The next prime is 81375313. The reversal of 81375305 is 50357318.

It is not a de Polignac number, because 81375305 - 2⁴ = 81375289 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 259829 + ... + 260141.

It is an arithmetic number, because the mean of its divisors is an integer number (3475980).

Almost surely, 2^81375305 is an apocalyptic number.

It is an amenable number.

81375305 is a deficient number, since it is larger than the sum of its proper divisors (29856055).

81375305 is a wasteful number, since it uses less digits than its factorization.

81375305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 81375305 is about 9020.8261816754. The cubic root of 81375305 is about 433.3420928538.

The spelling of 81375305 in words is "eighty-one million, three hundred seventy-five thousand, three hundred five".