1861800 has 96 divisors (see below), whose sum is σ = 6026400. Its totient is φ = 474880.

The previous prime is 1861787. The next prime is 1861807. The reversal of 1861800 is 81681.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861807) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17347 + ... + 17453.

It is an arithmetic number, because the mean of its divisors is an integer number (62775).

2^1861800 is an apocalyptic number.

1861800 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 1861800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3013200).

1861800 is an abundant number, since it is smaller than the sum of its proper divisors (4164600).

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

1861800 is a wasteful number, since it uses less digits than its factorization.

1861800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 1861800 is about 1364.4779221373. The cubic root of 1861800 is about 123.0205531124.

The spelling of 1861800 in words is "one million, eight hundred sixty-one thousand, eight hundred".