646445999 has 2 divisors, whose sum is σ = 646446000. Its totient is φ = 646445998.

The previous prime is 646445977. The next prime is 646446041. The reversal of 646445999 is 999544646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646445999 - 2²⁴ = 629668783 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 (646445959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323222999 + 323223000.

It is an arithmetic number, because the mean of its divisors is an integer number (323223000).

Almost surely, 2^646445999 is an apocalyptic number.

646445999 is a deficient number, since it is larger than the sum of its proper divisors (1).

646445999 is an equidigital number, since it uses as much as digits as its factorization.

646445999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8398080, while the sum is 56.

The square root of 646445999 is about 25425.3023384187. The cubic root of 646445999 is about 864.6574424040.

The spelling of 646445999 in words is "six hundred forty-six million, four hundred forty-five thousand, nine hundred ninety-nine".