81989922 has 32 divisors (see below), whose sum is σ = 187776000. Its totient is φ = 23379408.

The previous prime is 81989893. The next prime is 81989933. The reversal of 81989922 is 22998918.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23529 + ... + 26787.

It is an arithmetic number, because the mean of its divisors is an integer number (5868000).

Almost surely, 2^81989922 is an apocalyptic number.

81989922 is an abundant number, since it is smaller than the sum of its proper divisors (105786078).

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

81989922 is a wasteful number, since it uses less digits than its factorization.

81989922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3870.

The product of its digits is 186624, while the sum is 48.

The square root of 81989922 is about 9054.8286565788. The cubic root of 81989922 is about 434.4303496020.

The spelling of 81989922 in words is "eighty-one million, nine hundred eighty-nine thousand, nine hundred twenty-two".