99121905 has 48 divisors (see below), whose sum is σ = 175954896. Its totient is φ = 51609600.

The previous prime is 99121901. The next prime is 99121909. The reversal of 99121905 is 50912199.

It is an interprime number because it is at equal distance from previous prime (99121901) and next prime (99121909).

It can be written as a sum of positive squares in 8 ways, for example, as 5574321 + 93547584 = 2361^2 + 9672^2 .

It is not a de Polignac number, because 99121905 - 2² = 99121901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 99121905.

It is not an unprimeable number, because it can be changed into a prime (99121901) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 513489 + ... + 513681.

It is an arithmetic number, because the mean of its divisors is an integer number (3665727).

Almost surely, 2^99121905 is an apocalyptic number.

It is an amenable number.

99121905 is a deficient number, since it is larger than the sum of its proper divisors (76832991).

99121905 is a wasteful number, since it uses less digits than its factorization.

99121905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 415 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 99121905 is about 9955.9984431497. The cubic root of 99121905 is about 462.7963019759.

The spelling of 99121905 in words is "ninety-nine million, one hundred twenty-one thousand, nine hundred five".