99612021 has 16 divisors (see below), whose sum is σ = 138444800. Its totient is φ = 63635760.

The previous prime is 99612017. The next prime is 99612053. The reversal of 99612021 is 12021699.

It is a happy number.

It is not a de Polignac number, because 99612021 - 2² = 99612017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 99612021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99612221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4380 + ... + 14778.

It is an arithmetic number, because the mean of its divisors is an integer number (8652800).

Almost surely, 2^99612021 is an apocalyptic number.

It is an amenable number.

99612021 is a deficient number, since it is larger than the sum of its proper divisors (38832779).

99612021 is a wasteful number, since it uses less digits than its factorization.

99612021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10536.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 99612021 is about 9980.5821974472. The cubic root of 99612021 is about 463.5578256993.

The spelling of 99612021 in words is "ninety-nine million, six hundred twelve thousand, twenty-one".