640522237 has 2 divisors, whose sum is σ = 640522238. Its totient is φ = 640522236.

The previous prime is 640522229. The next prime is 640522247. The reversal of 640522237 is 732225046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 636754756 + 3767481 = 25234^2 + 1941^2 .

It is a cyclic number.

It is not a de Polignac number, because 640522237 - 2³ = 640522229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640522199 and 640522208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640522247) 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, 320261118 + 320261119.

It is an arithmetic number, because the mean of its divisors is an integer number (320261119).

Almost surely, 2^640522237 is an apocalyptic number.

It is an amenable number.

640522237 is a deficient number, since it is larger than the sum of its proper divisors (1).

640522237 is an equidigital number, since it uses as much as digits as its factorization.

640522237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 640522237 is about 25308.5407915984. The cubic root of 640522237 is about 862.0082134326.

The spelling of 640522237 in words is "six hundred forty million, five hundred twenty-two thousand, two hundred thirty-seven".