1861000 has 32 divisors (see below), whose sum is σ = 4357080. Its totient is φ = 744000.

The previous prime is 1860983. The next prime is 1861001. The reversal of 1861000 is 1681.

It can be written as a sum of positive squares in 4 ways, for example, as 70756 + 1790244 = 266^2 + 1338^2 .

It is not an unprimeable number, because it can be changed into a prime (1861001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70 + ... + 1930.

2^1861000 is an apocalyptic number.

1861000 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 1861000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2178540).

1861000 is an abundant number, since it is smaller than the sum of its proper divisors (2496080).

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

1861000 is a wasteful number, since it uses less digits than its factorization.

1861000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882 (or 1868 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1861000 is about 1364.1847382228. The cubic root of 1861000 is about 123.0029302847.

Adding to 1861000 its reverse (1681), we get a palindrome (1862681).

The spelling of 1861000 in words is "one million, eight hundred sixty-one thousand".