1811906 has 8 divisors (see below), whose sum is σ = 2728704. Its totient is φ = 902340.

The previous prime is 1811903. The next prime is 1811923. The reversal of 1811906 is 6091181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1811903) 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 in 3 ways as a sum of consecutive naturals, for example, 1130 + ... + 2213.

It is an arithmetic number, because the mean of its divisors is an integer number (341088).

2^1811906 is an apocalyptic number.

1811906 is a deficient number, since it is larger than the sum of its proper divisors (916798).

1811906 is a wasteful number, since it uses less digits than its factorization.

1811906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3616.

The product of its (nonzero) digits is 432, while the sum is 26.

The square root of 1811906 is about 1346.0705776444. The cubic root of 1811906 is about 121.9116533192.

Subtracting 1811906 from its reverse (6091181), we obtain a triangular number (4279275 = T₂₉₂₅).

It can be divided in two parts, 1811 and 906, that multiplied together give a triangular number (1640766 = T₁₈₁₁).

The spelling of 1811906 in words is "one million, eight hundred eleven thousand, nine hundred six".