1813906 has 8 divisors (see below), whose sum is σ = 2732220. Its totient is φ = 903168.

The previous prime is 1813901. The next prime is 1813913. The reversal of 1813906 is 6093181.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1798281 + 15625 = 1341^2 + 125^2 .

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

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1813901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1251 + ... + 2278.

2^1813906 is an apocalyptic number.

1813906 is a deficient number, since it is larger than the sum of its proper divisors (918314).

1813906 is a wasteful number, since it uses less digits than its factorization.

1813906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3788.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1813906 is about 1346.8132758478. The cubic root of 1813906 is about 121.9564925935.

Subtracting 1813906 from its reverse (6093181), we obtain a triangular number (4279275 = T₂₉₂₅).

It can be divided in two parts, 1813 and 906, that multiplied together give a triangular number (1642578 = T₁₈₁₂).

The spelling of 1813906 in words is "one million, eight hundred thirteen thousand, nine hundred six".