99172915 has 4 divisors (see below), whose sum is σ = 119007504. Its totient is φ = 79338328.

The previous prime is 99172907. The next prime is 99172919. The reversal of 99172915 is 51927199.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51927199 = 71 ⋅731369.

It is a cyclic number.

It is not a de Polignac number, because 99172915 - 2³ = 99172907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99172919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9917287 + ... + 9917296.

It is an arithmetic number, because the mean of its divisors is an integer number (29751876).

Almost surely, 2^99172915 is an apocalyptic number.

99172915 is a deficient number, since it is larger than the sum of its proper divisors (19834589).

99172915 is a wasteful number, since it uses less digits than its factorization.

99172915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19834588.

The product of its digits is 51030, while the sum is 43.

The square root of 99172915 is about 9958.5598858469. The cubic root of 99172915 is about 462.8756762607.

The spelling of 99172915 in words is "ninety-nine million, one hundred seventy-two thousand, nine hundred fifteen".