81373724 has 12 divisors (see below), whose sum is σ = 148595664. Its totient is φ = 38917824.

The previous prime is 81373717. The next prime is 81373741. The reversal of 81373724 is 42737318.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 442157 + ... + 442340.

It is an arithmetic number, because the mean of its divisors is an integer number (12382972).

Almost surely, 2^81373724 is an apocalyptic number.

It is an amenable number.

81373724 is a deficient number, since it is larger than the sum of its proper divisors (67221940).

81373724 is a wasteful number, since it uses less digits than its factorization.

81373724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884524 (or 884522 counting only the distinct ones).

The product of its digits is 28224, while the sum is 35.

The square root of 81373724 is about 9020.7385506953. The cubic root of 81373724 is about 433.3392864402.

The spelling of 81373724 in words is "eighty-one million, three hundred seventy-three thousand, seven hundred twenty-four".