99981171 has 24 divisors (see below), whose sum is σ = 146510000. Its totient is φ = 65696832.

The previous prime is 99981163. The next prime is 99981179. The reversal of 99981171 is 17118999.

It is an interprime number because it is at equal distance from previous prime (99981163) and next prime (99981179).

It is not a de Polignac number, because 99981171 - 2³ = 99981163 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99981179) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 286305 + ... + 286653.

Almost surely, 2^99981171 is an apocalyptic number.

99981171 is a deficient number, since it is larger than the sum of its proper divisors (46528829).

99981171 is a wasteful number, since it uses less digits than its factorization.

99981171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723 (or 720 counting only the distinct ones).

The product of its digits is 40824, while the sum is 45.

The square root of 99981171 is about 9999.0585056794. The cubic root of 99981171 is about 464.1297493739.

The spelling of 99981171 in words is "ninety-nine million, nine hundred eighty-one thousand, one hundred seventy-one".