1865881 has 2 divisors, whose sum is σ = 1865882. Its totient is φ = 1865880.

The previous prime is 1865863. The next prime is 1865887. The reversal of 1865881 is 1885681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1798281 + 67600 = 1341^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1865881 - 2⁵ = 1865849 is a prime.

It is a super-2 number, since 2×1865881² = 6963023812322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1865881.

It is not a weakly prime, because it can be changed into another prime (1865887) 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 as a sum of consecutive naturals, namely, 932940 + 932941.

It is an arithmetic number, because the mean of its divisors is an integer number (932941).

2^1865881 is an apocalyptic number.

It is an amenable number.

1865881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1865881 is an equidigital number, since it uses as much as digits as its factorization.

1865881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15360, while the sum is 37.

The square root of 1865881 is about 1365.9725473083. The cubic root of 1865881 is about 123.1103730896.

The spelling of 1865881 in words is "one million, eight hundred sixty-five thousand, eight hundred eighty-one".