99911421 has 8 divisors (see below), whose sum is σ = 148016960. Its totient is φ = 66607596.

The previous prime is 99911417. The next prime is 99911423. The reversal of 99911421 is 12411999.

It is not a de Polignac number, because 99911421 - 2² = 99911417 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 (99911423) 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 7 ways as a sum of consecutive naturals, for example, 1850185 + ... + 1850238.

It is an arithmetic number, because the mean of its divisors is an integer number (18502120).

Almost surely, 2^99911421 is an apocalyptic number.

It is an amenable number.

99911421 is a deficient number, since it is larger than the sum of its proper divisors (48105539).

99911421 is a wasteful number, since it uses less digits than its factorization.

99911421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700432 (or 3700426 counting only the distinct ones).

The product of its digits is 5832, while the sum is 36.

The square root of 99911421 is about 9995.5700687855. The cubic root of 99911421 is about 464.0217937767.

The spelling of 99911421 in words is "ninety-nine million, nine hundred eleven thousand, four hundred twenty-one".