681090 has 32 divisors (see below), whose sum is σ = 1662336. Its totient is φ = 178560.

The previous prime is 681089. The next prime is 681091. The reversal of 681090 is 90186.

681090 = T₁₅₁ + T₁₅₂ + ... + T₁₉₅.

It is an interprime number because it is at equal distance from previous prime (681089) and next prime (681091).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 681090.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681090.

It is not an unprimeable number, because it can be changed into a prime (681091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2035 + ... + 2345.

It is an arithmetic number, because the mean of its divisors is an integer number (51948).

2⁶⁸¹⁰⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (831168).

681090 is an abundant number, since it is smaller than the sum of its proper divisors (981246).

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

681090 is a wasteful number, since it uses less digits than its factorization.

681090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 681090 is about 825.2817700640. The cubic root of 681090 is about 87.9835540892.

The spelling of 681090 in words is "six hundred eighty-one thousand, ninety".