640550188731907 has 2 divisors, whose sum is σ = 640550188731908. Its totient is φ = 640550188731906.

The previous prime is 640550188731847. The next prime is 640550188732009. The reversal of 640550188731907 is 709137881055046.

640550188731907 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640550188731907 is a prime.

It is not a weakly prime, because it can be changed into another prime (640550188731007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320275094365953 + 320275094365954.

It is an arithmetic number, because the mean of its divisors is an integer number (320275094365954).

Almost surely, 2^{640550188731907} is an apocalyptic number.

640550188731907 is a deficient number, since it is larger than the sum of its proper divisors (1).

640550188731907 is an equidigital number, since it uses as much as digits as its factorization.

640550188731907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 50803200, while the sum is 64.

The spelling of 640550188731907 in words is "six hundred forty trillion, five hundred fifty billion, one hundred eighty-eight million, seven hundred thirty-one thousand, nine hundred seven".