681517980 has 432 divisors, whose sum is σ = 2561963040. Its totient is φ = 145474560.

The previous prime is 681517979. The next prime is 681518017. The reversal of 681517980 is 89715186.

681517980 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8211019 + ... + 8211101.

It is an arithmetic number, because the mean of its divisors is an integer number (5930470).

Almost surely, 2^681517980 is an apocalyptic number.

681517980 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 681517980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1280981520).

681517980 is an abundant number, since it is smaller than the sum of its proper divisors (1880445060).

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

681517980 is a wasteful number, since it uses less digits than its factorization.

681517980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The square root of 681517980 is about 26105.8993332925. The cubic root of 681517980 is about 880.0197912216.

The spelling of 681517980 in words is "six hundred eighty-one million, five hundred seventeen thousand, nine hundred eighty".