197653891 has 2 divisors, whose sum is σ = 197653892. Its totient is φ = 197653890.

The previous prime is 197653877. The next prime is 197653901. The reversal of 197653891 is 198356791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 197653891 - 2¹³ = 197645699 is a prime.

It is not a weakly prime, because it can be changed into another prime (197653811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98826945 + 98826946.

It is an arithmetic number, because the mean of its divisors is an integer number (98826946).

Almost surely, 2^197653891 is an apocalyptic number.

197653891 is a deficient number, since it is larger than the sum of its proper divisors (1).

197653891 is an equidigital number, since it uses as much as digits as its factorization.

197653891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 49.

The square root of 197653891 is about 14058.9434524789. The cubic root of 197653891 is about 582.5078594358.

The spelling of 197653891 in words is "one hundred ninety-seven million, six hundred fifty-three thousand, eight hundred ninety-one".