1812213 has 20 divisors (see below), whose sum is σ = 2917068. Its totient is φ = 1114560.

The previous prime is 1812199. The next prime is 1812227. The reversal of 1812213 is 3122181.

It is an interprime number because it is at equal distance from previous prime (1812199) and next prime (1812227).

It can be written as a sum of positive squares in 2 ways, for example, as 777924 + 1034289 = 882^2 + 1017^2 .

It is not a de Polignac number, because 1812213 - 2¹² = 1808117 is a prime.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1812233) 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, 193 + ... + 1913.

2^1812213 is an apocalyptic number.

1812213 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1812213 is a deficient number, since it is larger than the sum of its proper divisors (1104855).

1812213 is a wasteful number, since it uses less digits than its factorization.

1812213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1746 (or 1737 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1812213 is about 1346.1846084397. The cubic root of 1812213 is about 121.9185382908.

Adding to 1812213 its reverse (3122181), we get a palindrome (4934394).

It can be divided in two parts, 1812 and 213, that added together give a square (2025 = 45²).

The spelling of 1812213 in words is "one million, eight hundred twelve thousand, two hundred thirteen".