639448412640 has 96 divisors (see below), whose sum is σ = 2019047609376. Its totient is φ = 170114488320.

The previous prime is 639448412591. The next prime is 639448412693. The reversal of 639448412640 is 46214844936.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1380087 + ... + 1784246.

It is an arithmetic number, because the mean of its divisors is an integer number (21031745931).

Almost surely, 2^639448412640 is an apocalyptic number.

639448412640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

639448412640 is an abundant number, since it is smaller than the sum of its proper divisors (1379599196736).

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

639448412640 is a wasteful number, since it uses less digits than its factorization.

639448412640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3164772 (or 3164764 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 51.

The spelling of 639448412640 in words is "six hundred thirty-nine billion, four hundred forty-eight million, four hundred twelve thousand, six hundred forty".