681838 has 4 divisors (see below), whose sum is σ = 1022760. Its totient is φ = 340918.

The previous prime is 681833. The next prime is 681839. The reversal of 681838 is 838186.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170458 + ... + 170461.

It is an arithmetic number, because the mean of its divisors is an integer number (255690).

2⁶⁸¹⁸³⁸ is an apocalyptic number.

681838 is a deficient number, since it is larger than the sum of its proper divisors (340922).

681838 is a wasteful number, since it uses less digits than its factorization.

681838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340921.

The product of its digits is 9216, while the sum is 34.

The square root of 681838 is about 825.7348242626. The cubic root of 681838 is about 88.0157513127.

The spelling of 681838 in words is "six hundred eighty-one thousand, eight hundred thirty-eight".