81945522 has 48 divisors (see below), whose sum is σ = 181014912. Its totient is φ = 26788320.

The previous prime is 81945517. The next prime is 81945533. The reversal of 81945522 is 22554918.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 302247 + ... + 302517.

It is an arithmetic number, because the mean of its divisors is an integer number (3771144).

Almost surely, 2^81945522 is an apocalyptic number.

81945522 is an abundant number, since it is smaller than the sum of its proper divisors (99069390).

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

81945522 is a wasteful number, since it uses less digits than its factorization.

81945522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543 (or 540 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 81945522 is about 9052.3765940221. The cubic root of 81945522 is about 434.3519164242.

The spelling of 81945522 in words is "eighty-one million, nine hundred forty-five thousand, five hundred twenty-two".