646156139 has 2 divisors, whose sum is σ = 646156140. Its totient is φ = 646156138.

The previous prime is 646156129. The next prime is 646156153. The reversal of 646156139 is 931651646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646156139 - 2²⁸ = 377720683 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646156096 and 646156105.

It is not a weakly prime, because it can be changed into another prime (646156129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323078069 + 323078070.

It is an arithmetic number, because the mean of its divisors is an integer number (323078070).

Almost surely, 2^646156139 is an apocalyptic number.

646156139 is a deficient number, since it is larger than the sum of its proper divisors (1).

646156139 is an equidigital number, since it uses as much as digits as its factorization.

646156139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 646156139 is about 25419.6014720924. The cubic root of 646156139 is about 864.5281884648.

The spelling of 646156139 in words is "six hundred forty-six million, one hundred fifty-six thousand, one hundred thirty-nine".