81313524 has 24 divisors (see below), whose sum is σ = 210813120. Its totient is φ = 27104472.

The previous prime is 81313513. The next prime is 81313543. The reversal of 81313524 is 42531318.

It is a happy number.

81313524 is a `hidden beast` number, since 8 + 131 + 3 + 524 = 666.

It is a super-2 number, since 2×81313524² = 13223778370597152, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376344 + ... + 376559.

It is an arithmetic number, because the mean of its divisors is an integer number (8783880).

Almost surely, 2^81313524 is an apocalyptic number.

It is an amenable number.

81313524 is an abundant number, since it is smaller than the sum of its proper divisors (129499596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81313524 is a wasteful number, since it uses less digits than its factorization.

81313524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752916 (or 752908 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 81313524 is about 9017.4011777230. The cubic root of 81313524 is about 433.2323991084.

The spelling of 81313524 in words is "eighty-one million, three hundred thirteen thousand, five hundred twenty-four".