197191091 has 4 divisors (see below), whose sum is σ = 197688192. Its totient is φ = 196693992.

The previous prime is 197191079. The next prime is 197191103. The reversal of 197191091 is 190191791.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (197191079) and next prime (197191103).

It is a cyclic number.

It is not a de Polignac number, because 197191091 - 2¹⁴ = 197174707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197191021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247955 + ... + 248748.

It is an arithmetic number, because the mean of its divisors is an integer number (49422048).

Almost surely, 2^197191091 is an apocalyptic number.

197191091 is a deficient number, since it is larger than the sum of its proper divisors (497101).

197191091 is an equidigital number, since it uses as much as digits as its factorization.

197191091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497100.

The product of its (nonzero) digits is 5103, while the sum is 38.

The square root of 197191091 is about 14042.4745326456. The cubic root of 197191091 is about 582.0528632167.

The spelling of 197191091 in words is "one hundred ninety-seven million, one hundred ninety-one thousand, ninety-one".