681291840 has 56 divisors (see below), whose sum is σ = 2163104640. Its totient is φ = 181677568.

The previous prime is 681291833. The next prime is 681291857. The reversal of 681291840 is 48192186.

681291840 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353880 + ... + 355799.

Almost surely, 2^681291840 is an apocalyptic number.

681291840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

681291840 is an abundant number, since it is smaller than the sum of its proper divisors (1481812800).

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

681291840 is a wasteful number, since it uses less digits than its factorization.

681291840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709699 (or 709689 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 681291840 is about 26101.5677690058. The cubic root of 681291840 is about 879.9224449559.

The spelling of 681291840 in words is "six hundred eighty-one million, two hundred ninety-one thousand, eight hundred forty".