646118131 has 2 divisors, whose sum is σ = 646118132. Its totient is φ = 646118130.

The previous prime is 646118119. The next prime is 646118147. The reversal of 646118131 is 131811646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646118131 - 2¹¹ = 646116083 is a prime.

It is a super-2 number, since 2×646118131² = 834937278413866322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 646118093 and 646118102.

It is not a weakly prime, because it can be changed into another prime (646118111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323059065 + 323059066.

It is an arithmetic number, because the mean of its divisors is an integer number (323059066).

Almost surely, 2^646118131 is an apocalyptic number.

646118131 is a deficient number, since it is larger than the sum of its proper divisors (1).

646118131 is an equidigital number, since it uses as much as digits as its factorization.

646118131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 31.

The square root of 646118131 is about 25418.8538490625. The cubic root of 646118131 is about 864.5112371276.

Adding to 646118131 its reverse (131811646), we get a palindrome (777929777).

The spelling of 646118131 in words is "six hundred forty-six million, one hundred eighteen thousand, one hundred thirty-one".