99000021 has 4 divisors (see below), whose sum is σ = 132000032. Its totient is φ = 66000012.

The previous prime is 99000007. The next prime is 99000023. The reversal of 99000021 is 12000099.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 99000021 - 2⁷ = 98999893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99000023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16500001 + ... + 16500006.

It is an arithmetic number, because the mean of its divisors is an integer number (33000008).

Almost surely, 2^99000021 is an apocalyptic number.

It is an amenable number.

99000021 is a deficient number, since it is larger than the sum of its proper divisors (33000011).

99000021 is a wasteful number, since it uses less digits than its factorization.

99000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33000010.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 99000021 is about 9949.8754263558. The cubic root of 99000021 is about 462.6065336278.

The spelling of 99000021 in words is "ninety-nine million, twenty-one", and thus it is an aban number and an uban number.