639280565742 has 96 divisors (see below), whose sum is σ = 1608772136832. Its totient is φ = 167858502336.

The previous prime is 639280565741. The next prime is 639280565783. The reversal of 639280565742 is 247565082936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639280565741) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 499173 + ... + 1236015.

It is an arithmetic number, because the mean of its divisors is an integer number (16758043092).

Almost surely, 2^639280565742 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639280565742, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (804386068416).

639280565742 is an abundant number, since it is smaller than the sum of its proper divisors (969491571090).

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

639280565742 is a wasteful number, since it uses less digits than its factorization.

639280565742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737102 (or 737095 counting only the distinct ones).

The product of its (nonzero) digits is 21772800, while the sum is 57.

The spelling of 639280565742 in words is "six hundred thirty-nine billion, two hundred eighty million, five hundred sixty-five thousand, seven hundred forty-two".