646310591 has 2 divisors, whose sum is σ = 646310592. Its totient is φ = 646310590.

The previous prime is 646310579. The next prime is 646310611. The reversal of 646310591 is 195013646.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646310591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646310551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323155295 + 323155296.

It is an arithmetic number, because the mean of its divisors is an integer number (323155296).

Almost surely, 2^646310591 is an apocalyptic number.

646310591 is a deficient number, since it is larger than the sum of its proper divisors (1).

646310591 is an equidigital number, since it uses as much as digits as its factorization.

646310591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 646310591 is about 25422.6393397696. The cubic root of 646310591 is about 864.5970662803.

The spelling of 646310591 in words is "six hundred forty-six million, three hundred ten thousand, five hundred ninety-one".