81900926 has 4 divisors (see below), whose sum is σ = 122851392. Its totient is φ = 40950462.

The previous prime is 81900893. The next prime is 81900947. The reversal of 81900926 is 62900918.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20475230 + ... + 20475233.

It is an arithmetic number, because the mean of its divisors is an integer number (30712848).

Almost surely, 2^81900926 is an apocalyptic number.

81900926 is a deficient number, since it is larger than the sum of its proper divisors (40950466).

81900926 is a wasteful number, since it uses less digits than its factorization.

81900926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40950465.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 81900926 is about 9049.9130382562. The cubic root of 81900926 is about 434.2731084856.

The spelling of 81900926 in words is "eighty-one million, nine hundred thousand, nine hundred twenty-six".