681314640 has 80 divisors (see below), whose sum is σ = 2116680000. Its totient is φ = 181287936.

The previous prime is 681314591. The next prime is 681314657. The reversal of 681314640 is 46413186.

It is a tau number, because it is divible by the number of its divisors (80).

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, 116916 + ... + 122604.

It is an arithmetic number, because the mean of its divisors is an integer number (26458500).

Almost surely, 2^681314640 is an apocalyptic number.

681314640 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 681314640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1058340000).

681314640 is an abundant number, since it is smaller than the sum of its proper divisors (1435365360).

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

681314640 is a wasteful number, since it uses less digits than its factorization.

681314640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6204 (or 6198 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 681314640 is about 26102.0045207260. The cubic root of 681314640 is about 879.9322606260.

It can be divided in two parts, 6813146 and 40, that added together give a palindrome (6813186).

The spelling of 681314640 in words is "six hundred eighty-one million, three hundred fourteen thousand, six hundred forty".