681907 has 4 divisors (see below), whose sum is σ = 703936. Its totient is φ = 659880.

The previous prime is 681899. The next prime is 681913. The reversal of 681907 is 709186.

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 681907 - 2³ = 681899 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 21997 = 681907 / (6 + 8 + 1 + 9 + 0 + 7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681977) 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, 10968 + ... + 11029.

It is an arithmetic number, because the mean of its divisors is an integer number (175984).

2⁶⁸¹⁹⁰⁷ is an apocalyptic number.

681907 is a deficient number, since it is larger than the sum of its proper divisors (22029).

681907 is a wasteful number, since it uses less digits than its factorization.

681907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22028.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 681907 is about 825.7766041733. The cubic root of 681907 is about 88.0187201909.

The spelling of 681907 in words is "six hundred eighty-one thousand, nine hundred seven".