1851861 has 16 divisors (see below), whose sum is σ = 2852928. Its totient is φ = 1056000.

The previous prime is 1851859. The next prime is 1851869. The reversal of 1851861 is 1681581.

It is a happy number.

It is not a de Polignac number, because 1851861 - 2¹ = 1851859 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1851869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1090 + ... + 2211.

It is an arithmetic number, because the mean of its divisors is an integer number (178308).

2^1851861 is an apocalyptic number.

1851861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1851861 is a deficient number, since it is larger than the sum of its proper divisors (1001067).

1851861 is a wasteful number, since it uses less digits than its factorization.

1851861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332.

The product of its digits is 1920, while the sum is 30.

The square root of 1851861 is about 1360.8309961197. The cubic root of 1851861 is about 122.8012521667.

The spelling of 1851861 in words is "one million, eight hundred fifty-one thousand, eight hundred sixty-one".