639744521387622 has 256 divisors, whose sum is σ = 1598236142469120. Its totient is φ = 166771664640000.

The previous prime is 639744521387611. The next prime is 639744521387639. The reversal of 639744521387622 is 226783125447936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6271892622 + ... + 6271994622.

It is an arithmetic number, because the mean of its divisors is an integer number (6243109931520).

Almost surely, 2^{639744521387622} is an apocalyptic number.

639744521387622 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 639744521387622, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799118071234560).

639744521387622 is an abundant number, since it is smaller than the sum of its proper divisors (958491621081498).

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

639744521387622 is a wasteful number, since it uses less digits than its factorization.

639744521387622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105979.

The product of its digits is 731566080, while the sum is 69.

The spelling of 639744521387622 in words is "six hundred thirty-nine trillion, seven hundred forty-four billion, five hundred twenty-one million, three hundred eighty-seven thousand, six hundred twenty-two".