681213840 has 320 divisors, whose sum is σ = 2361753600. Its totient is φ = 161740800.

The previous prime is 681213829. The next prime is 681213847. The reversal of 681213840 is 48312186.

681213840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (681213847) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8622921 + ... + 8622999.

It is an arithmetic number, because the mean of its divisors is an integer number (7380480).

Almost surely, 2^681213840 is an apocalyptic number.

681213840 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 681213840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180876800).

681213840 is an abundant number, since it is smaller than the sum of its proper divisors (1680539760).

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

681213840 is a wasteful number, since it uses less digits than its factorization.

681213840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 681213840 is about 26100.0735631147. The cubic root of 681213840 is about 879.8888633754. Note that the first 4 decimals are identical.

The spelling of 681213840 in words is "six hundred eighty-one million, two hundred thirteen thousand, eight hundred forty".