81171275 has 12 divisors (see below), whose sum is σ = 101032224. Its totient is φ = 64692000.

The previous prime is 81171257. The next prime is 81171317. The reversal of 81171275 is 57217118.

It is not a de Polignac number, because 81171275 - 2¹² = 81167179 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 785 + ... + 12765.

It is an arithmetic number, because the mean of its divisors is an integer number (8419352).

Almost surely, 2^81171275 is an apocalyptic number.

81171275 is a deficient number, since it is larger than the sum of its proper divisors (19860949).

81171275 is a wasteful number, since it uses less digits than its factorization.

81171275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12262 (or 12257 counting only the distinct ones).

The product of its digits is 3920, while the sum is 32.

The square root of 81171275 is about 9009.5102530604. The cubic root of 81171275 is about 432.9796209565.

The spelling of 81171275 in words is "eighty-one million, one hundred seventy-one thousand, two hundred seventy-five".