639797760 has 240 divisors, whose sum is σ = 2532980736. Its totient is φ = 146202624.

The previous prime is 639797749. The next prime is 639797761. The reversal of 639797760 is 67797936.

It is a tau number, because it is divible by the number of its divisors (240).

It is a junction number, because it is equal to n+sod(n) for n = 639797697 and 639797706.

It is not an unprimeable number, because it can be changed into a prime (639797761) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 159297 + ... + 163263.

Almost surely, 2^639797760 is an apocalyptic number.

639797760 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 639797760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1266490368).

639797760 is an abundant number, since it is smaller than the sum of its proper divisors (1893182976).

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

639797760 is a wasteful number, since it uses less digits than its factorization.

639797760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4003 (or 3984 counting only the distinct ones).

The product of its (nonzero) digits is 3000564, while the sum is 54.

The square root of 639797760 is about 25294.2238465623. The cubic root of 639797760 is about 861.6830929347.

The spelling of 639797760 in words is "six hundred thirty-nine million, seven hundred ninety-seven thousand, seven hundred sixty".