99921375 has 24 divisors (see below), whose sum is σ = 180126960. Its totient is φ = 53290800.

The previous prime is 99921373. The next prime is 99921383. The reversal of 99921375 is 57312999.

It is a happy number.

It is not a de Polignac number, because 99921375 - 2¹ = 99921373 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 99921375.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99921373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43285 + ... + 45534.

It is an arithmetic number, because the mean of its divisors is an integer number (7505290).

Almost surely, 2^99921375 is an apocalyptic number.

99921375 is a deficient number, since it is larger than the sum of its proper divisors (80205585).

99921375 is a wasteful number, since it uses less digits than its factorization.

99921375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88840 (or 88827 counting only the distinct ones).

The product of its digits is 153090, while the sum is 45.

The square root of 99921375 is about 9996.0679769597. The cubic root of 99921375 is about 464.0372031580.

The spelling of 99921375 in words is "ninety-nine million, nine hundred twenty-one thousand, three hundred seventy-five".