681378671 has 4 divisors (see below), whose sum is σ = 681893472. Its totient is φ = 680863872.

The previous prime is 681378647. The next prime is 681378689. The reversal of 681378671 is 176873186.

681378671 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 a de Polignac number, because none of the positive numbers 2^k-681378671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681378641) 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, 255410 + ... + 258063.

It is an arithmetic number, because the mean of its divisors is an integer number (170473368).

Almost surely, 2^681378671 is an apocalyptic number.

681378671 is a deficient number, since it is larger than the sum of its proper divisors (514801).

681378671 is a wasteful number, since it uses less digits than its factorization.

681378671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514800.

The product of its digits is 338688, while the sum is 47.

The square root of 681378671 is about 26103.2310452174. The cubic root of 681378671 is about 879.9598255592.

The spelling of 681378671 in words is "six hundred eighty-one million, three hundred seventy-eight thousand, six hundred seventy-one".