2051811 has 20 divisors (see below), whose sum is σ = 3115992. Its totient is φ = 1345248.

The previous prime is 2051801. The next prime is 2051821. The reversal of 2051811 is 1181502.

It is an interprime number because it is at equal distance from previous prime (2051801) and next prime (2051821).

It is not a de Polignac number, because 2051811 - 2¹⁰ = 2050787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2051801) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5740 + ... + 6086.

2^2051811 is an apocalyptic number.

2051811 is a deficient number, since it is larger than the sum of its proper divisors (1064181).

2051811 is an equidigital number, since it uses as much as digits as its factorization.

2051811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 2051811 is about 1432.4143953479. The cubic root of 2051811 is about 127.0708059914.

It can be divided in two parts, 205 and 1811, that added together give a triangular number (2016 = T₆₃).

The spelling of 2051811 in words is "two million, fifty-one thousand, eight hundred eleven".