640427222 has 4 divisors (see below), whose sum is σ = 960640836. Its totient is φ = 320213610.

The previous prime is 640427219. The next prime is 640427237. The reversal of 640427222 is 222724046.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 222724046 = 2 ⋅111362023.

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 as a sum of consecutive naturals, namely, 160106804 + ... + 160106807.

It is an arithmetic number, because the mean of its divisors is an integer number (240160209).

Almost surely, 2^640427222 is an apocalyptic number.

640427222 is a deficient number, since it is larger than the sum of its proper divisors (320213614).

640427222 is a wasteful number, since it uses less digits than its factorization.

640427222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320213613.

The product of its (nonzero) digits is 10752, while the sum is 29.

The square root of 640427222 is about 25306.6635888653. The cubic root of 640427222 is about 861.9655879229.

The spelling of 640427222 in words is "six hundred forty million, four hundred twenty-seven thousand, two hundred twenty-two".