681438 has 16 divisors (see below), whose sum is σ = 1374480. Its totient is φ = 225216.

The previous prime is 681427. The next prime is 681449. The reversal of 681438 is 834186.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (681427) and next prime (681449).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 408 + ... + 1236.

It is an arithmetic number, because the mean of its divisors is an integer number (85905).

2⁶⁸¹⁴³⁸ is an apocalyptic number.

681438 is an abundant number, since it is smaller than the sum of its proper divisors (693042).

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

681438 is a wasteful number, since it uses less digits than its factorization.

681438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 971.

The product of its digits is 4608, while the sum is 30.

The square root of 681438 is about 825.4925802210. The cubic root of 681438 is about 87.9985364770.

The spelling of 681438 in words is "six hundred eighty-one thousand, four hundred thirty-eight".