81613576 has 32 divisors (see below), whose sum is σ = 172327680. Its totient is φ = 35899200.

The previous prime is 81613561. The next prime is 81613589. The reversal of 81613576 is 67531618.

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, 12231 + ... + 17686.

It is an arithmetic number, because the mean of its divisors is an integer number (5385240).

Almost surely, 2^81613576 is an apocalyptic number.

It is an amenable number.

81613576 is an abundant number, since it is smaller than the sum of its proper divisors (90714104).

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

81613576 is a wasteful number, since it uses less digits than its factorization.

81613576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29965 (or 29961 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The square root of 81613576 is about 9034.0232454870. The cubic root of 81613576 is about 433.7646298913.

The spelling of 81613576 in words is "eighty-one million, six hundred thirteen thousand, five hundred seventy-six".