639799127940 has 288 divisors, whose sum is σ = 2212992762624. Its totient is φ = 137633771520.

The previous prime is 639799127911. The next prime is 639799127959. The reversal of 639799127940 is 49721997936.

It is a super-2 number, since 2×639799127940² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 17124480 + ... + 17161800.

It is an arithmetic number, because the mean of its divisors is an integer number (7684002648).

Almost surely, 2^639799127940 is an apocalyptic number.

639799127940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639799127940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1106496381312).

639799127940 is an abundant number, since it is smaller than the sum of its proper divisors (1573193634684).

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

639799127940 is a wasteful number, since it uses less digits than its factorization.

639799127940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37385 (or 37355 counting only the distinct ones).

The product of its (nonzero) digits is 46294416, while the sum is 66.

It can be divided in two parts, 63979 and 9127940, that added together give a palindrome (9191919).

The spelling of 639799127940 in words is "six hundred thirty-nine billion, seven hundred ninety-nine million, one hundred twenty-seven thousand, nine hundred forty".