646406204051 has 2 divisors, whose sum is σ = 646406204052. Its totient is φ = 646406204050.

The previous prime is 646406204033. The next prime is 646406204071. The reversal of 646406204051 is 150402604646.

646406204051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646406204051 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 646406203996 and 646406204014.

It is not a weakly prime, because it can be changed into another prime (646406204071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323203102025 + 323203102026.

It is an arithmetic number, because the mean of its divisors is an integer number (323203102026).

Almost surely, 2^646406204051 is an apocalyptic number.

646406204051 is a deficient number, since it is larger than the sum of its proper divisors (1).

646406204051 is an equidigital number, since it uses as much as digits as its factorization.

646406204051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 646406204051 its reverse (150402604646), we get a palindrome (796808808697).

The spelling of 646406204051 in words is "six hundred forty-six billion, four hundred six million, two hundred four thousand, fifty-one".