681406 has 16 divisors (see below), whose sum is σ = 1140480. Its totient is φ = 302680.

The previous prime is 681403. The next prime is 681407. The reversal of 681406 is 604186.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 705 + ... + 1363.

It is an arithmetic number, because the mean of its divisors is an integer number (71280).

2⁶⁸¹⁴⁰⁶ is an apocalyptic number.

681406 is a deficient number, since it is larger than the sum of its proper divisors (459074).

681406 is a wasteful number, since it uses less digits than its factorization.

681406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 681406 is about 825.4731976267. The cubic root of 681406 is about 87.9971589992.

The spelling of 681406 in words is "six hundred eighty-one thousand, four hundred six".