681909740 has 24 divisors (see below), whose sum is σ = 1449267120. Its totient is φ = 269476928.

The previous prime is 681909737. The next prime is 681909757. The reversal of 681909740 is 47909186.

681909740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 681909691 and 681909700.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 203735 + ... + 207054.

It is an arithmetic number, because the mean of its divisors is an integer number (60386130).

Almost surely, 2^681909740 is an apocalyptic number.

It is an amenable number.

681909740 is an abundant number, since it is smaller than the sum of its proper divisors (767357380).

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

681909740 is a wasteful number, since it uses less digits than its factorization.

681909740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410881 (or 410879 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 681909740 is about 26113.4015402054. The cubic root of 681909740 is about 880.1883808139.

The spelling of 681909740 in words is "six hundred eighty-one million, nine hundred nine thousand, seven hundred forty".