81616782 has 16 divisors (see below), whose sum is σ = 175790160. Its totient is φ = 25112832.

The previous prime is 81616781. The next prime is 81616789. The reversal of 81616782 is 28761618.

It is a super-2 number, since 2×81616782² = 13322598208071048, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 81616782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81616781) 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, 523107 + ... + 523262.

It is an arithmetic number, because the mean of its divisors is an integer number (10986885).

Almost surely, 2^81616782 is an apocalyptic number.

81616782 is an abundant number, since it is smaller than the sum of its proper divisors (94173378).

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

81616782 is a wasteful number, since it uses less digits than its factorization.

81616782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046387.

The product of its digits is 32256, while the sum is 39.

The square root of 81616782 is about 9034.2006840672. The cubic root of 81616782 is about 433.7703096293.

The spelling of 81616782 in words is "eighty-one million, six hundred sixteen thousand, seven hundred eighty-two".