171620191 has 2 divisors, whose sum is σ = 171620192. Its totient is φ = 171620190.

The previous prime is 171620161. The next prime is 171620209. The reversal of 171620191 is 191026171.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 171620191 - 2¹⁷ = 171489119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171620101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85810095 + 85810096.

It is an arithmetic number, because the mean of its divisors is an integer number (85810096).

Almost surely, 2^171620191 is an apocalyptic number.

171620191 is a deficient number, since it is larger than the sum of its proper divisors (1).

171620191 is an equidigital number, since it uses as much as digits as its factorization.

171620191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 28.

The square root of 171620191 is about 13100.3889636911. The cubic root of 171620191 is about 555.7201278943.

The spelling of 171620191 in words is "one hundred seventy-one million, six hundred twenty thousand, one hundred ninety-one".