81571263 has 16 divisors (see below), whose sum is σ = 111697152. Its totient is φ = 52920000.

The previous prime is 81571247. The next prime is 81571283. The reversal of 81571263 is 36217518.

It is not a de Polignac number, because 81571263 - 2⁴ = 81571247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81571283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77088 + ... + 78138.

It is an arithmetic number, because the mean of its divisors is an integer number (6981072).

Almost surely, 2^81571263 is an apocalyptic number.

81571263 is a deficient number, since it is larger than the sum of its proper divisors (30125889).

81571263 is a wasteful number, since it uses less digits than its factorization.

81571263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1726.

The product of its digits is 10080, while the sum is 33.

The square root of 81571263 is about 9031.6810727572. The cubic root of 81571263 is about 433.6896543930.

The spelling of 81571263 in words is "eighty-one million, five hundred seventy-one thousand, two hundred sixty-three".