99972109 has 4 divisors (see below), whose sum is σ = 100942816. Its totient is φ = 99001404.

The previous prime is 99972079. The next prime is 99972157. The reversal of 99972109 is 90127999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 99972109 - 2¹¹ = 99970061 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 (99972709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 485199 + ... + 485404.

It is an arithmetic number, because the mean of its divisors is an integer number (25235704).

Almost surely, 2^99972109 is an apocalyptic number.

It is an amenable number.

99972109 is a deficient number, since it is larger than the sum of its proper divisors (970707).

99972109 is a wasteful number, since it uses less digits than its factorization.

99972109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 970706.

The product of its (nonzero) digits is 91854, while the sum is 46.

The square root of 99972109 is about 9998.6053527480. The cubic root of 99972109 is about 464.1157264973.

The spelling of 99972109 in words is "ninety-nine million, nine hundred seventy-two thousand, one hundred nine".