638840740022 has 16 divisors (see below), whose sum is σ = 971477851920. Its totient is φ = 315015599232.

The previous prime is 638840740019. The next prime is 638840740049. The reversal of 638840740022 is 220047048836.

It is a happy number.

It is a super-2 number, since 2×638840740022² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1425629 + ... + 1819367.

It is an arithmetic number, because the mean of its divisors is an integer number (60717365745).

Almost surely, 2^638840740022 is an apocalyptic number.

638840740022 is a deficient number, since it is larger than the sum of its proper divisors (332637111898).

638840740022 is a wasteful number, since it uses less digits than its factorization.

638840740022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404927.

The product of its (nonzero) digits is 516096, while the sum is 44.

Adding to 638840740022 its reverse (220047048836), we get a palindrome (858887788858).

The spelling of 638840740022 in words is "six hundred thirty-eight billion, eight hundred forty million, seven hundred forty thousand, twenty-two".