81583772 has 12 divisors (see below), whose sum is σ = 142873080. Its totient is φ = 40762896.

The previous prime is 81583753. The next prime is 81583781. The reversal of 81583772 is 27738518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143 + ... + 12774.

It is an arithmetic number, because the mean of its divisors is an integer number (11906090).

Almost surely, 2^81583772 is an apocalyptic number.

It is an amenable number.

81583772 is a deficient number, since it is larger than the sum of its proper divisors (61289308).

81583772 is a wasteful number, since it uses less digits than its factorization.

81583772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14500 (or 14498 counting only the distinct ones).

The product of its digits is 94080, while the sum is 41.

The square root of 81583772 is about 9032.3735529483. The cubic root of 81583772 is about 433.7118221124.

The spelling of 81583772 in words is "eighty-one million, five hundred eighty-three thousand, seven hundred seventy-two".