681539040 has 432 divisors, whose sum is σ = 2917500768. Its totient is φ = 143603712.

The previous prime is 681539021. The next prime is 681539077. The reversal of 681539040 is 40935186.

681539040 is a `hidden beast` number, since 6 + 81 + 539 + 0 + 40 = 666.

681539040 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 681538986 and 681539004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 916909 + ... + 917651.

It is an arithmetic number, because the mean of its divisors is an integer number (6753474).

Almost surely, 2^681539040 is an apocalyptic number.

681539040 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 681539040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1458750384).

681539040 is an abundant number, since it is smaller than the sum of its proper divisors (2235961728).

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

681539040 is a wasteful number, since it uses less digits than its factorization.

681539040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791 (or 773 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 681539040 is about 26106.3026872822. The cubic root of 681539040 is about 880.0288558031.

The spelling of 681539040 in words is "six hundred eighty-one million, five hundred thirty-nine thousand, forty".