81616524 has 96 divisors (see below), whose sum is σ = 226146816. Its totient is φ = 22625280.

The previous prime is 81616501. The next prime is 81616543. The reversal of 81616524 is 42561618.

It is a super-2 number, since 2×81616524² = 13322513979685152, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82537 + ... + 83519.

It is an arithmetic number, because the mean of its divisors is an integer number (2355696).

Almost surely, 2^81616524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81616524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113073408).

81616524 is an abundant number, since it is smaller than the sum of its proper divisors (144530292).

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

81616524 is a wasteful number, since it uses less digits than its factorization.

81616524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055 (or 1053 counting only the distinct ones).

The product of its digits is 11520, while the sum is 33.

The square root of 81616524 is about 9034.1864049841. The cubic root of 81616524 is about 433.7698525630.

It can be divided in two parts, 816 and 16524, that multiplied together give a square (13483584 = 3672²).

The spelling of 81616524 in words is "eighty-one million, six hundred sixteen thousand, five hundred twenty-four".