81601612 has 12 divisors (see below), whose sum is σ = 143360280. Its totient is φ = 40641536.

The previous prime is 81601601. The next prime is 81601627. The reversal of 81601612 is 21610618.

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, 38662 + ... + 40717.

It is an arithmetic number, because the mean of its divisors is an integer number (11946690).

Almost surely, 2^81601612 is an apocalyptic number.

It is an amenable number.

81601612 is a deficient number, since it is larger than the sum of its proper divisors (61758668).

81601612 is a wasteful number, since it uses less digits than its factorization.

81601612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79640 (or 79638 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81601612 is about 9033.3610577680. The cubic root of 81601612 is about 433.7434331988.

The spelling of 81601612 in words is "eighty-one million, six hundred one thousand, six hundred twelve".