664465691 has 2 divisors, whose sum is σ = 664465692. Its totient is φ = 664465690.

The previous prime is 664465657. The next prime is 664465709. The reversal of 664465691 is 196564466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664465691 - 2¹⁴ = 664449307 is a prime.

It is a super-2 number, since 2×664465691² = 883029309032214962, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (664465091) 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, 332232845 + 332232846.

It is an arithmetic number, because the mean of its divisors is an integer number (332232846).

Almost surely, 2^664465691 is an apocalyptic number.

664465691 is a deficient number, since it is larger than the sum of its proper divisors (1).

664465691 is an equidigital number, since it uses as much as digits as its factorization.

664465691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 47.

The square root of 664465691 is about 25777.2320275083. The cubic root of 664465691 is about 872.6180401485.

The spelling of 664465691 in words is "six hundred sixty-four million, four hundred sixty-five thousand, six hundred ninety-one".