640903238 has 16 divisors (see below), whose sum is σ = 994775040. Its totient is φ = 309361800.

The previous prime is 640903217. The next prime is 640903243. The reversal of 640903238 is 832309046.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 640903198 and 640903207.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13643 + ... + 38313.

It is an arithmetic number, because the mean of its divisors is an integer number (62173440).

Almost surely, 2^640903238 is an apocalyptic number.

640903238 is a deficient number, since it is larger than the sum of its proper divisors (353871802).

640903238 is a wasteful number, since it uses less digits than its factorization.

640903238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25123.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 640903238 is about 25316.0667956142. The cubic root of 640903238 is about 862.1790952927.

The spelling of 640903238 in words is "six hundred forty million, nine hundred three thousand, two hundred thirty-eight".