646380131 has 2 divisors, whose sum is σ = 646380132. Its totient is φ = 646380130.

The previous prime is 646380083. The next prime is 646380139. The reversal of 646380131 is 131083646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646380131 - 2⁶ = 646380067 is a prime.

It is a super-2 number, since 2×646380131² = 835614547503154322, which contains 22 as substring.

It is a Sophie Germain prime.

It is equal to p_33614924 and since 646380131 and 33614924 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (646380139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323190065 + 323190066.

It is an arithmetic number, because the mean of its divisors is an integer number (323190066).

Almost surely, 2^646380131 is an apocalyptic number.

646380131 is a deficient number, since it is larger than the sum of its proper divisors (1).

646380131 is an equidigital number, since it uses as much as digits as its factorization.

646380131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 646380131 is about 25424.0069815912. The cubic root of 646380131 is about 864.6280740365.

The spelling of 646380131 in words is "six hundred forty-six million, three hundred eighty thousand, one hundred thirty-one".