680721408 has 220 divisors, whose sum is σ = 2110293240. Its totient is φ = 218308608.

The previous prime is 680721403. The next prime is 680721413. The reversal of 680721408 is 804127086.

It is an interprime number because it is at equal distance from previous prime (680721403) and next prime (680721413).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680721403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2405235 + ... + 2405517.

It is an arithmetic number, because the mean of its divisors is an integer number (9592242).

Almost surely, 2^680721408 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 680721408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1055146620).

680721408 is an abundant number, since it is smaller than the sum of its proper divisors (1429571832).

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

680721408 is a wasteful number, since it uses less digits than its factorization.

680721408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 680721408 is about 26090.6383210530. The cubic root of 680721408 is about 879.6767959095.

The spelling of 680721408 in words is "six hundred eighty million, seven hundred twenty-one thousand, four hundred eight".