197109091 has 2 divisors, whose sum is σ = 197109092. Its totient is φ = 197109090.

The previous prime is 197109079. The next prime is 197109131. The reversal of 197109091 is 190901791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 197109091 - 2⁷ = 197108963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 197109091.

It is not a weakly prime, because it can be changed into another prime (197109041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98554545 + 98554546.

It is an arithmetic number, because the mean of its divisors is an integer number (98554546).

Almost surely, 2^197109091 is an apocalyptic number.

197109091 is a deficient number, since it is larger than the sum of its proper divisors (1).

197109091 is an equidigital number, since it uses as much as digits as its factorization.

197109091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5103, while the sum is 37.

The square root of 197109091 is about 14039.5545157245. The cubic root of 197109091 is about 581.9721716874.

The spelling of 197109091 in words is "one hundred ninety-seven million, one hundred nine thousand, ninety-one".