99975891 has 8 divisors (see below), whose sum is σ = 140317120. Its totient is φ = 63142632.

The previous prime is 99975857. The next prime is 99975923. The reversal of 99975891 is 19857999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 99975891 - 2¹⁰ = 99974867 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1753963 = 99975891 / (9 + 9 + 9 + 7 + 5 + 8 + 9 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99975091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 876925 + ... + 877038.

It is an arithmetic number, because the mean of its divisors is an integer number (17539640).

Almost surely, 2^99975891 is an apocalyptic number.

99975891 is a deficient number, since it is larger than the sum of its proper divisors (40341229).

99975891 is a wasteful number, since it uses less digits than its factorization.

99975891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1753985.

The product of its digits is 1837080, while the sum is 57.

The square root of 99975891 is about 9998.7944773358. The cubic root of 99975891 is about 464.1215790082.

The spelling of 99975891 in words is "ninety-nine million, nine hundred seventy-five thousand, eight hundred ninety-one".