646459951 has 2 divisors, whose sum is σ = 646459952. Its totient is φ = 646459950.

The previous prime is 646459943. The next prime is 646459973. The reversal of 646459951 is 159954646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646459951 - 2³ = 646459943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646459895 and 646459904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646459351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323229975 + 323229976.

It is an arithmetic number, because the mean of its divisors is an integer number (323229976).

Almost surely, 2^646459951 is an apocalyptic number.

646459951 is a deficient number, since it is larger than the sum of its proper divisors (1).

646459951 is an equidigital number, since it uses as much as digits as its factorization.

646459951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1166400, while the sum is 49.

The square root of 646459951 is about 25425.5767092902. The cubic root of 646459951 is about 864.6636628843.

The spelling of 646459951 in words is "six hundred forty-six million, four hundred fifty-nine thousand, nine hundred fifty-one".