81572 has 6 divisors (see below), whose sum is σ = 142758. Its totient is φ = 40784.

The previous prime is 81569. The next prime is 81611. The reversal of 81572 is 27518.

It can be written as a sum of positive squares in only one way, i.e., 70756 + 10816 = 266^2 + 104^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10193 + ... + 10200.

It is an arithmetic number, because the mean of its divisors is an integer number (23793).

2⁸¹⁵⁷² is an apocalyptic number.

It is an amenable number.

81572 is a deficient number, since it is larger than the sum of its proper divisors (61186).

81572 is a wasteful number, since it uses less digits than its factorization.

81572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20397 (or 20395 counting only the distinct ones).

The product of its digits is 560, while the sum is 23.

The square root of 81572 is about 285.6081231338. The cubic root of 81572 is about 43.3690960524.

The spelling of 81572 in words is "eighty-one thousand, five hundred seventy-two".