680240640 has 160 divisors (see below), whose sum is σ = 2269783296. Its totient is φ = 173465600.

The previous prime is 680240629. The next prime is 680240653. The reversal of 680240640 is 46042086.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 680240598 and 680240607.

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, 174715 + ... + 178565.

Almost surely, 2^680240640 is an apocalyptic number.

680240640 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 680240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1134891648).

680240640 is an abundant number, since it is smaller than the sum of its proper divisors (1589542656).

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

680240640 is a wasteful number, since it uses less digits than its factorization.

680240640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3900 (or 3884 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 680240640 is about 26081.4232740470. The cubic root of 680240640 is about 879.4696528932.

The spelling of 680240640 in words is "six hundred eighty million, two hundred forty thousand, six hundred forty".