81524 has 12 divisors (see below), whose sum is σ = 144900. Its totient is φ = 40128.

The previous prime is 81517. The next prime is 81527. The reversal of 81524 is 42518.

It can be written as a sum of positive squares in 2 ways, for example, as 48400 + 33124 = 220^2 + 182^2 .

Its product of digits (320) is a multiple of the sum of its prime divisors (320).

It is a junction number, because it is equal to n+sod(n) for n = 81496 and 81505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242 + ... + 470.

It is an arithmetic number, because the mean of its divisors is an integer number (12075).

2⁸¹⁵²⁴ is an apocalyptic number.

It is an amenable number.

81524 is a deficient number, since it is larger than the sum of its proper divisors (63376).

81524 is a wasteful number, since it uses less digits than its factorization.

81524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322 (or 320 counting only the distinct ones).

The product of its digits is 320, while the sum is 20.

The square root of 81524 is about 285.5240795450. The cubic root of 81524 is about 43.3605877201.

The spelling of 81524 in words is "eighty-one thousand, five hundred twenty-four".