664355191 has 2 divisors, whose sum is σ = 664355192. Its totient is φ = 664355190.

The previous prime is 664355179. The next prime is 664355213. The reversal of 664355191 is 191553466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664355191 - 2⁷ = 664355063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664353191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332177595 + 332177596.

It is an arithmetic number, because the mean of its divisors is an integer number (332177596).

Almost surely, 2^664355191 is an apocalyptic number.

664355191 is a deficient number, since it is larger than the sum of its proper divisors (1).

664355191 is an equidigital number, since it uses as much as digits as its factorization.

664355191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 40.

The square root of 664355191 is about 25775.0885740476. The cubic root of 664355191 is about 872.5696656223.

The spelling of 664355191 in words is "six hundred sixty-four million, three hundred fifty-five thousand, one hundred ninety-one".