99231921 has 6 divisors (see below), whose sum is σ = 143335010. Its totient is φ = 66154608.

The previous prime is 99231919. The next prime is 99231929. The reversal of 99231921 is 12913299.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 94303521 + 4928400 = 9711^2 + 2220^2 .

It is not a de Polignac number, because 99231921 - 2¹ = 99231919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99231929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5512876 + ... + 5512893.

Almost surely, 2^99231921 is an apocalyptic number.

It is an amenable number.

99231921 is a deficient number, since it is larger than the sum of its proper divisors (44103089).

99231921 is a wasteful number, since it uses less digits than its factorization.

99231921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11025775 (or 11025772 counting only the distinct ones).

The product of its digits is 8748, while the sum is 36.

The square root of 99231921 is about 9961.5220222615. The cubic root of 99231921 is about 462.9674588042.

The spelling of 99231921 in words is "ninety-nine million, two hundred thirty-one thousand, nine hundred twenty-one".