640252 has 12 divisors (see below), whose sum is σ = 1137640. Its totient is φ = 315216.

The previous prime is 640249. The next prime is 640259. The reversal of 640252 is 252046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 927 + ... + 1462.

2⁶⁴⁰²⁵² is an apocalyptic number.

It is an amenable number.

640252 is a deficient number, since it is larger than the sum of its proper divisors (497388).

640252 is a wasteful number, since it uses less digits than its factorization.

640252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2460 (or 2458 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 640252 is about 800.1574844991. The cubic root of 640252 is about 86.1886968992.

Adding to 640252 its reverse (252046), we get a palindrome (892298).

The spelling of 640252 in words is "six hundred forty thousand, two hundred fifty-two".