640422252 has 36 divisors (see below), whose sum is σ = 1620255000. Its totient is φ = 213288192.

The previous prime is 640422239. The next prime is 640422271. The reversal of 640422252 is 252224046.

It is a happy number.

640422252 is a `hidden beast` number, since 6 + 404 + 2 + 2 + 252 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37843 + ... + 52085.

Almost surely, 2^640422252 is an apocalyptic number.

It is an amenable number.

640422252 is an abundant number, since it is smaller than the sum of its proper divisors (979832748).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640422252 is a wasteful number, since it uses less digits than its factorization.

640422252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15502 (or 15497 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The square root of 640422252 is about 25306.5653931939. The cubic root of 640422252 is about 861.9633581717.

Adding to 640422252 its reverse (252224046), we get a palindrome (892646298).

The spelling of 640422252 in words is "six hundred forty million, four hundred twenty-two thousand, two hundred fifty-two".