81623886 has 16 divisors (see below), whose sum is σ = 171840000. Its totient is φ = 25775928.

The previous prime is 81623881. The next prime is 81623903. The reversal of 81623886 is 68832618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81623881) 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, 357886 + ... + 358113.

It is an arithmetic number, because the mean of its divisors is an integer number (10740000).

Almost surely, 2^81623886 is an apocalyptic number.

81623886 is an abundant number, since it is smaller than the sum of its proper divisors (90216114).

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

81623886 is a wasteful number, since it uses less digits than its factorization.

81623886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716023.

The product of its digits is 110592, while the sum is 42.

The square root of 81623886 is about 9034.5938480930. The cubic root of 81623886 is about 433.7828945202.

The spelling of 81623886 in words is "eighty-one million, six hundred twenty-three thousand, eight hundred eighty-six".