639920760 has 128 divisors (see below), whose sum is σ = 2028499200. Its totient is φ = 161049600.

The previous prime is 639920759. The next prime is 639920761. The reversal of 639920760 is 67029936.

It is an interprime number because it is at equal distance from previous prime (639920759) and next prime (639920761).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639920761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1064460 + ... + 1065060.

It is an arithmetic number, because the mean of its divisors is an integer number (15847650).

Almost surely, 2^639920760 is an apocalyptic number.

639920760 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 639920760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1014249600).

639920760 is an abundant number, since it is smaller than the sum of its proper divisors (1388578440).

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

639920760 is a wasteful number, since it uses less digits than its factorization.

639920760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 1097 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 42.

The square root of 639920760 is about 25296.6551148566. The cubic root of 639920760 is about 861.7383084188.

The spelling of 639920760 in words is "six hundred thirty-nine million, nine hundred twenty thousand, seven hundred sixty".