81369524 has 12 divisors (see below), whose sum is σ = 142495584. Its totient is φ = 40656504.

The previous prime is 81369511. The next prime is 81369527. The reversal of 81369524 is 42596318.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81369527) 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, 257 + ... + 12759.

It is an arithmetic number, because the mean of its divisors is an integer number (11874632).

Almost surely, 2^81369524 is an apocalyptic number.

It is an amenable number.

81369524 is a deficient number, since it is larger than the sum of its proper divisors (61126060).

81369524 is a wasteful number, since it uses less digits than its factorization.

81369524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14134 (or 14132 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 81369524 is about 9020.5057507880. The cubic root of 81369524 is about 433.3318308955.

The spelling of 81369524 in words is "eighty-one million, three hundred sixty-nine thousand, five hundred twenty-four".