1811387 has 2 divisors, whose sum is σ = 1811388. Its totient is φ = 1811386.

The previous prime is 1811377. The next prime is 1811389. The reversal of 1811387 is 7831181.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1811387 - 2⁴ = 1811371 is a prime.

It is a super-2 number, since 2×1811387² = 6562245727538, which contains 22 as substring.

Together with 1811389, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1811389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 905693 + 905694.

It is an arithmetic number, because the mean of its divisors is an integer number (905694).

2^1811387 is an apocalyptic number.

1811387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1811387 is an equidigital number, since it uses as much as digits as its factorization.

1811387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 29.

The square root of 1811387 is about 1345.8777804838. The cubic root of 1811387 is about 121.9000121358.

The spelling of 1811387 in words is "one million, eight hundred eleven thousand, three hundred eighty-seven".