639742423320 has 1536 divisors, whose sum is σ = 2873713489920. Its totient is φ = 119160668160.

The previous prime is 639742423297. The next prime is 639742423337. The reversal of 639742423320 is 23324247936.

639742423320 is a `hidden beast` number, since 6 + 3 + 9 + 74 + 242 + 332 + 0 = 666.

639742423320 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 2183421094 + ... + 2183421386.

It is an arithmetic number, because the mean of its divisors is an integer number (1870907220).

Almost surely, 2^639742423320 is an apocalyptic number.

639742423320 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 639742423320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1436856744960).

639742423320 is an abundant number, since it is smaller than the sum of its proper divisors (2233971066600).

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

639742423320 is a wasteful number, since it uses less digits than its factorization.

639742423320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 45.

The spelling of 639742423320 in words is "six hundred thirty-nine billion, seven hundred forty-two million, four hundred twenty-three thousand, three hundred twenty".