640547177 has 2 divisors, whose sum is σ = 640547178. Its totient is φ = 640547176.

The previous prime is 640547143. The next prime is 640547183. The reversal of 640547177 is 771745046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632824336 + 7722841 = 25156^2 + 2779^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640547177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640547137) 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, 320273588 + 320273589.

It is an arithmetic number, because the mean of its divisors is an integer number (320273589).

Almost surely, 2^640547177 is an apocalyptic number.

It is an amenable number.

640547177 is a deficient number, since it is larger than the sum of its proper divisors (1).

640547177 is an equidigital number, since it uses as much as digits as its factorization.

640547177 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 164640, while the sum is 41.

The square root of 640547177 is about 25309.0335058453. The cubic root of 640547177 is about 862.0194012856.

The spelling of 640547177 in words is "six hundred forty million, five hundred forty-seven thousand, one hundred seventy-seven".