81922918 has 64 divisors (see below), whose sum is σ = 162155520. Its totient is φ = 30096000.

The previous prime is 81922873. The next prime is 81922957.

81922918 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81922918² = 13422728987269448, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 357628 + ... + 357856.

It is an arithmetic number, because the mean of its divisors is an integer number (2533680).

Almost surely, 2^81922918 is an apocalyptic number.

81922918 is a deficient number, since it is larger than the sum of its proper divisors (80232602).

81922918 is a wasteful number, since it uses less digits than its factorization.

81922918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373.

The product of its digits is 20736, while the sum is 40.

The square root of 81922918 is about 9051.1279960014. The cubic root of 81922918 is about 434.3119752806.

The spelling of 81922918 in words is "eighty-one million, nine hundred twenty-two thousand, nine hundred eighteen".