2011861 has 2 divisors, whose sum is σ = 2011862. Its totient is φ = 2011860.

The previous prime is 2011843. The next prime is 2011897. The reversal of 2011861 is 1681102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1918225 + 93636 = 1385^2 + 306^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011861 - 2⁷ = 2011733 is a prime.

It is a super-3 number, since 3×2011861³ = 24429533305712611143, which contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2011811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005930 + 1005931.

It is an arithmetic number, because the mean of its divisors is an integer number (1005931).

2^2011861 is an apocalyptic number.

It is an amenable number.

2011861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011861 is an equidigital number, since it uses as much as digits as its factorization.

2011861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 2011861 is about 1418.4008601238. The cubic root of 2011861 is about 126.2406796374.

Adding to 2011861 its reverse (1681102), we get a palindrome (3692963).

It can be divided in two parts, 20 and 11861, that added together give a square (11881 = 109²).

The spelling of 2011861 in words is "two million, eleven thousand, eight hundred sixty-one".