681986747 has 4 divisors (see below), whose sum is σ = 734447280. Its totient is φ = 629526216.

The previous prime is 681986717. The next prime is 681986749. The reversal of 681986747 is 747689186.

681986747 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681986747 - 2²⁸ = 413551291 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681986692 and 681986701.

It is not an unprimeable number, because it can be changed into a prime (681986749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26230247 + ... + 26230272.

It is an arithmetic number, because the mean of its divisors is an integer number (183611820).

Almost surely, 2^681986747 is an apocalyptic number.

681986747 is a deficient number, since it is larger than the sum of its proper divisors (52460533).

681986747 is a wasteful number, since it uses less digits than its factorization.

681986747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52460532.

The product of its digits is 4064256, while the sum is 56.

The square root of 681986747 is about 26114.8759713693. The cubic root of 681986747 is about 880.2215123323.

The spelling of 681986747 in words is "six hundred eighty-one million, nine hundred eighty-six thousand, seven hundred forty-seven".