81099924 has 24 divisors (see below), whose sum is σ = 190972320. Its totient is φ = 26784864.

The previous prime is 81099919. The next prime is 81099929. The reversal of 81099924 is 42999018.

It is an interprime number because it is at equal distance from previous prime (81099919) and next prime (81099929).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81099929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29694 + ... + 32309.

It is an arithmetic number, because the mean of its divisors is an integer number (7957180).

Almost surely, 2^81099924 is an apocalyptic number.

It is an amenable number.

81099924 is an abundant number, since it is smaller than the sum of its proper divisors (109872396).

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

81099924 is a wasteful number, since it uses less digits than its factorization.

81099924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62119 (or 62117 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 81099924 is about 9005.5496223162. The cubic root of 81099924 is about 432.8527181601.

The spelling of 81099924 in words is "eighty-one million, ninety-nine thousand, nine hundred twenty-four".