197671891 has 2 divisors, whose sum is σ = 197671892. Its totient is φ = 197671890.

The previous prime is 197671853. The next prime is 197671921. The reversal of 197671891 is 198176791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 197671891 - 2⁹ = 197671379 is a prime.

It is not a weakly prime, because it can be changed into another prime (197671091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98835945 + 98835946.

It is an arithmetic number, because the mean of its divisors is an integer number (98835946).

Almost surely, 2^197671891 is an apocalyptic number.

197671891 is a deficient number, since it is larger than the sum of its proper divisors (1).

197671891 is an equidigital number, since it uses as much as digits as its factorization.

197671891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 49.

The square root of 197671891 is about 14059.5835998084. The cubic root of 197671891 is about 582.5255415621.

The spelling of 197671891 in words is "one hundred ninety-seven million, six hundred seventy-one thousand, eight hundred ninety-one".