640639122 has 16 divisors (see below), whose sum is σ = 1286009472. Its totient is φ = 212757840.

The previous prime is 640639099. The next prime is 640639123. The reversal of 640639122 is 221936046.

It is not an unprimeable number, because it can be changed into a prime (640639123) by changing a digit.

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, 195373 + ... + 198624.

It is an arithmetic number, because the mean of its divisors is an integer number (80375592).

Almost surely, 2^640639122 is an apocalyptic number.

640639122 is an abundant number, since it is smaller than the sum of its proper divisors (645370350).

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

640639122 is a wasteful number, since it uses less digits than its factorization.

640639122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394273.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 640639122 is about 25310.8498869556. The cubic root of 640639122 is about 862.0606444522.

The spelling of 640639122 in words is "six hundred forty million, six hundred thirty-nine thousand, one hundred twenty-two".