99800172 has 18 divisors (see below), whose sum is σ = 252272748. Its totient is φ = 33266712.

The previous prime is 99800167. The next prime is 99800177. The reversal of 99800172 is 27100899.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (99800167) and next prime (99800177).

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2772227 = 99800172 / (9 + 9 + 8 + 0 + 0 + 1 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (99800177) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1386078 + ... + 1386149.

Almost surely, 2^99800172 is an apocalyptic number.

It is an amenable number.

99800172 is an abundant number, since it is smaller than the sum of its proper divisors (152472576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99800172 is a wasteful number, since it uses less digits than its factorization.

99800172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2772237 (or 2772232 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 99800172 is about 9990.0036036030. The cubic root of 99800172 is about 463.8495040564.

The spelling of 99800172 in words is "ninety-nine million, eight hundred thousand, one hundred seventy-two".