81375164 has 12 divisors (see below), whose sum is σ = 153360984. Its totient is φ = 37557744.

The previous prime is 81375097. The next prime is 81375167. The reversal of 81375164 is 46157318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81375167) 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 3 ways as a sum of consecutive naturals, for example, 782402 + ... + 782505.

It is an arithmetic number, because the mean of its divisors is an integer number (12780082).

Almost surely, 2^81375164 is an apocalyptic number.

It is an amenable number.

81375164 is a deficient number, since it is larger than the sum of its proper divisors (71985820).

81375164 is a wasteful number, since it uses less digits than its factorization.

81375164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564924 (or 1564922 counting only the distinct ones).

The product of its digits is 20160, while the sum is 35.

The square root of 81375164 is about 9020.8183664233. The cubic root of 81375164 is about 433.3418425679.

The spelling of 81375164 in words is "eighty-one million, three hundred seventy-five thousand, one hundred sixty-four".