1806840 has 128 divisors (see below), whose sum is σ = 6912000. Its totient is φ = 411264.

The previous prime is 1806839. The next prime is 1806841. The reversal of 1806840 is 486081.

1806840 = 109² + 110² + ... + 188².

It is an interprime number because it is at equal distance from previous prime (1806839) and next prime (1806841).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7441 + ... + 7679.

It is an arithmetic number, because the mean of its divisors is an integer number (54000).

2^1806840 is an apocalyptic number.

1806840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1806840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3456000).

1806840 is an abundant number, since it is smaller than the sum of its proper divisors (5105160).

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

1806840 is a wasteful number, since it uses less digits than its factorization.

1806840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 1806840 is about 1344.1874869229. The cubic root of 1806840 is about 121.7979276019.

The spelling of 1806840 in words is "one million, eight hundred six thousand, eight hundred forty".