81608612 has 6 divisors (see below), whose sum is σ = 142815078. Its totient is φ = 40804304.

The previous prime is 81608609. The next prime is 81608617. The reversal of 81608612 is 21680618.

It can be written as a sum of positive squares in only one way, i.e., 81288256 + 320356 = 9016^2 + 566^2 .

It is not an unprimeable number, because it can be changed into a prime (81608617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201073 + ... + 10201080.

It is an arithmetic number, because the mean of its divisors is an integer number (23802513).

Almost surely, 2^81608612 is an apocalyptic number.

It is an amenable number.

81608612 is a deficient number, since it is larger than the sum of its proper divisors (61206466).

81608612 is a wasteful number, since it uses less digits than its factorization.

81608612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20402157 (or 20402155 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 81608612 is about 9033.7485021446. The cubic root of 81608612 is about 433.7558353934.

The spelling of 81608612 in words is "eighty-one million, six hundred eight thousand, six hundred twelve".