639767480 has 64 divisors (see below), whose sum is σ = 1579305600. Its totient is φ = 231314560.

The previous prime is 639767473. The next prime is 639767483. The reversal of 639767480 is 84767936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639767483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74699 + ... + 82821.

It is an arithmetic number, because the mean of its divisors is an integer number (24676650).

Almost surely, 2^639767480 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639767480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (789652800).

639767480 is an abundant number, since it is smaller than the sum of its proper divisors (939538120).

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

639767480 is a wasteful number, since it uses less digits than its factorization.

639767480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8324 (or 8320 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 50.

The square root of 639767480 is about 25293.6252838536. The cubic root of 639767480 is about 861.6694989641.

The spelling of 639767480 in words is "six hundred thirty-nine million, seven hundred sixty-seven thousand, four hundred eighty".