97991171 has 2 divisors, whose sum is σ = 97991172. Its totient is φ = 97991170.

The previous prime is 97991141. The next prime is 97991183. The reversal of 97991171 is 17119979.

It is a strong prime.

It is an emirp because it is prime and its reverse (17119979) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 97991171 - 2²² = 93796867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (97991141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48995585 + 48995586.

It is an arithmetic number, because the mean of its divisors is an integer number (48995586).

Almost surely, 2^97991171 is an apocalyptic number.

97991171 is a deficient number, since it is larger than the sum of its proper divisors (1).

97991171 is an equidigital number, since it uses as much as digits as its factorization.

97991171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35721, while the sum is 44.

The square root of 97991171 is about 9899.0489947267. The cubic root of 97991171 is about 461.0297833676.

The spelling of 97991171 in words is "ninety-seven million, nine hundred ninety-one thousand, one hundred seventy-one".