81616502 has 16 divisors (see below), whose sum is σ = 136076112. Its totient is φ = 36397920.

The previous prime is 81616501. The next prime is 81616543. The reversal of 81616502 is 20561618.

It is a happy number.

It is a super-2 number, since 2×81616502² = 13322506797432008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81616501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33833 + ... + 36164.

It is an arithmetic number, because the mean of its divisors is an integer number (8504757).

Almost surely, 2^81616502 is an apocalyptic number.

81616502 is a deficient number, since it is larger than the sum of its proper divisors (54459610).

81616502 is a wasteful number, since it uses less digits than its factorization.

81616502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70063.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 81616502 is about 9034.1851873869. The cubic root of 81616502 is about 433.7698135883.

The spelling of 81616502 in words is "eighty-one million, six hundred sixteen thousand, five hundred two".