667163591 has 2 divisors, whose sum is σ = 667163592. Its totient is φ = 667163590.

The previous prime is 667163551. The next prime is 667163593. The reversal of 667163591 is 195361766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 667163591 - 2²² = 662969287 is a prime.

Together with 667163593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667163593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333581795 + 333581796.

It is an arithmetic number, because the mean of its divisors is an integer number (333581796).

Almost surely, 2^667163591 is an apocalyptic number.

667163591 is a deficient number, since it is larger than the sum of its proper divisors (1).

667163591 is an equidigital number, since it uses as much as digits as its factorization.

667163591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 204120, while the sum is 44.

The square root of 667163591 is about 25829.5100805261. The cubic root of 667163591 is about 873.7974625245.

It can be divided in two parts, 66716 and 3591, that added together give a palindrome (70307).

The spelling of 667163591 in words is "six hundred sixty-seven million, one hundred sixty-three thousand, five hundred ninety-one".