81946899 has 12 divisors (see below), whose sum is σ = 118630512. Its totient is φ = 54510000.

The previous prime is 81946873. The next prime is 81946927. The reversal of 81946899 is 99864918.

It is not a de Polignac number, because 81946899 - 2⁷ = 81946771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81946819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5727 + ... + 14024.

It is an arithmetic number, because the mean of its divisors is an integer number (9885876).

Almost surely, 2^81946899 is an apocalyptic number.

81946899 is a deficient number, since it is larger than the sum of its proper divisors (36683613).

81946899 is a wasteful number, since it uses less digits than its factorization.

81946899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20218 (or 20215 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 54.

The square root of 81946899 is about 9052.4526510775. The cubic root of 81946899 is about 434.3543493383.

The spelling of 81946899 in words is "eighty-one million, nine hundred forty-six thousand, eight hundred ninety-nine".