640348188157 has 2 divisors, whose sum is σ = 640348188158. Its totient is φ = 640348188156.

The previous prime is 640348188127. The next prime is 640348188167. The reversal of 640348188157 is 751881843046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 568306407321 + 72041780836 = 753861^2 + 268406^2 .

It is a cyclic number.

It is not a de Polignac number, because 640348188157 - 2²³ = 640339799549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640348188098 and 640348188107.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640348188127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320174094078 + 320174094079.

It is an arithmetic number, because the mean of its divisors is an integer number (320174094079).

Almost surely, 2^640348188157 is an apocalyptic number.

It is an amenable number.

640348188157 is a deficient number, since it is larger than the sum of its proper divisors (1).

640348188157 is an equidigital number, since it uses as much as digits as its factorization.

640348188157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5160960, while the sum is 55.

The spelling of 640348188157 in words is "six hundred forty billion, three hundred forty-eight million, one hundred eighty-eight thousand, one hundred fifty-seven".