646400659 has 2 divisors, whose sum is σ = 646400660. Its totient is φ = 646400658.

The previous prime is 646400647. The next prime is 646400701. The reversal of 646400659 is 956004646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646400659 - 2¹¹ = 646398611 is a prime.

It is not a weakly prime, because it can be changed into another prime (646400609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323200329 + 323200330.

It is an arithmetic number, because the mean of its divisors is an integer number (323200330).

Almost surely, 2^646400659 is an apocalyptic number.

646400659 is a deficient number, since it is larger than the sum of its proper divisors (1).

646400659 is an equidigital number, since it uses as much as digits as its factorization.

646400659 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 646400659 is about 25424.4106913022. The cubic root of 646400659 is about 864.6372270082.

The spelling of 646400659 in words is "six hundred forty-six million, four hundred thousand, six hundred fifty-nine".