1855861 has 4 divisors (see below), whose sum is σ = 2120992. Its totient is φ = 1590732.

The previous prime is 1855853. The next prime is 1855891. The reversal of 1855861 is 1685581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1855861 - 2³ = 1855853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1855811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132555 + ... + 132568.

It is an arithmetic number, because the mean of its divisors is an integer number (530248).

2^1855861 is an apocalyptic number.

It is an amenable number.

1855861 is a deficient number, since it is larger than the sum of its proper divisors (265131).

1855861 is an equidigital number, since it uses as much as digits as its factorization.

1855861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265130.

The product of its digits is 9600, while the sum is 34.

The square root of 1855861 is about 1362.2998935624. The cubic root of 1855861 is about 122.8896050483.

The spelling of 1855861 in words is "one million, eight hundred fifty-five thousand, eight hundred sixty-one".