640417139 has 2 divisors, whose sum is σ = 640417140. Its totient is φ = 640417138.

The previous prime is 640417117. The next prime is 640417147. The reversal of 640417139 is 931714046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640417139 - 2⁸ = 640416883 is a prime.

It is a super-2 number, since 2×640417139² = 820268223849890642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 640417099 and 640417108.

It is not a weakly prime, because it can be changed into another prime (640410139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320208569 + 320208570.

It is an arithmetic number, because the mean of its divisors is an integer number (320208570).

Almost surely, 2^640417139 is an apocalyptic number.

640417139 is a deficient number, since it is larger than the sum of its proper divisors (1).

640417139 is an equidigital number, since it uses as much as digits as its factorization.

640417139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 640417139 is about 25306.4643717766. The cubic root of 640417139 is about 861.9610642527.

The spelling of 640417139 in words is "six hundred forty million, four hundred seventeen thousand, one hundred thirty-nine".