1813890 has 32 divisors (see below), whose sum is σ = 4689216. Its totient is φ = 446400.

The previous prime is 1813853. The next prime is 1813897. The reversal of 1813890 is 983181.

1813890 = T₂₀₃ + T₂₀₄ + ... + T₂₆₇.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1813897) 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 15 ways as a sum of consecutive naturals, for example, 1936 + ... + 2715.

It is an arithmetic number, because the mean of its divisors is an integer number (146538).

2^1813890 is an apocalyptic number.

1813890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1813890 is an abundant number, since it is smaller than the sum of its proper divisors (2875326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1813890 is a wasteful number, since it uses less digits than its factorization.

1813890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 1813890 is about 1346.8073358874. The cubic root of 1813890 is about 121.9561340101.

The spelling of 1813890 in words is "one million, eight hundred thirteen thousand, eight hundred ninety".