81613156 has 9 divisors (see below), whose sum is σ = 142854649. Its totient is φ = 40797544.

The previous prime is 81613127. The next prime is 81613159. The reversal of 81613156 is 65131618.

The square root of 81613156 is 9034.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 324900 + 81288256 = 570^2 + 9016^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81613159) by changing a digit.

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 2 ways as a sum of consecutive naturals, for example, 15810 + ... + 20326.

Almost surely, 2^81613156 is an apocalyptic number.

81613156 is the 9034-th square number.

It is an amenable number.

81613156 is a deficient number, since it is larger than the sum of its proper divisors (61241493).

81613156 is an frugal number, since it uses more digits than its factorization.

81613156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9038 (or 4519 counting only the distinct ones).

The product of its digits is 4320, while the sum is 31.

The cubic root of 81613156 is about 433.7638858098.

The spelling of 81613156 in words is "eighty-one million, six hundred thirteen thousand, one hundred fifty-six".