664040687 has 2 divisors, whose sum is σ = 664040688. Its totient is φ = 664040686.

The previous prime is 664040623. The next prime is 664040711. The reversal of 664040687 is 786040466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664040687 - 2⁶ = 664040623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664040617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332020343 + 332020344.

It is an arithmetic number, because the mean of its divisors is an integer number (332020344).

Almost surely, 2^664040687 is an apocalyptic number.

664040687 is a deficient number, since it is larger than the sum of its proper divisors (1).

664040687 is an equidigital number, since it uses as much as digits as its factorization.

664040687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 664040687 is about 25768.9869222676. The cubic root of 664040687 is about 872.4319531609.

The spelling of 664040687 in words is "six hundred sixty-four million, forty thousand, six hundred eighty-seven".