81622899 has 24 divisors (see below), whose sum is σ = 125697312. Its totient is φ = 50860800.

The previous prime is 81622873. The next prime is 81622909. The reversal of 81622899 is 99822618.

It is not a de Polignac number, because 81622899 - 2¹⁶ = 81557363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81622859) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21337 + ... + 24869.

It is an arithmetic number, because the mean of its divisors is an integer number (5237388).

Almost surely, 2^81622899 is an apocalyptic number.

81622899 is a deficient number, since it is larger than the sum of its proper divisors (44074413).

81622899 is a wasteful number, since it uses less digits than its factorization.

81622899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3707 (or 3704 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 81622899 is about 9034.5392245537. The cubic root of 81622899 is about 433.7811460719.

The spelling of 81622899 in words is "eighty-one million, six hundred twenty-two thousand, eight hundred ninety-nine".