1805881 has 16 divisors (see below), whose sum is σ = 2304000. Its totient is φ = 1374480.

The previous prime is 1805879. The next prime is 1805887. The reversal of 1805881 is 1885081.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1805881 - 2¹ = 1805879 is a prime.

It is a super-2 number, since 2×1805881² = 6522412372322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1805887) 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, 3370 + ... + 3868.

It is an arithmetic number, because the mean of its divisors is an integer number (144000).

2^1805881 is an apocalyptic number.

1805881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1805881 is a deficient number, since it is larger than the sum of its proper divisors (498119).

1805881 is a wasteful number, since it uses less digits than its factorization.

1805881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564.

The product of its (nonzero) digits is 2560, while the sum is 31.

The square root of 1805881 is about 1343.8307185059. The cubic root of 1805881 is about 121.7763752631.

The spelling of 1805881 in words is "one million, eight hundred five thousand, eight hundred eighty-one".