1821212 has 12 divisors (see below), whose sum is σ = 3241560. Its totient is φ = 895056.

The previous prime is 1821191. The next prime is 1821233. The reversal of 1821212 is 2121281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1821191) and next prime (1821233).

It is a congruent number.

It is an unprimeable number.

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, 3623 + ... + 4094.

It is an arithmetic number, because the mean of its divisors is an integer number (270130).

2^1821212 is an apocalyptic number.

It is an amenable number.

1821212 is a deficient number, since it is larger than the sum of its proper divisors (1420348).

1821212 is a wasteful number, since it uses less digits than its factorization.

1821212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7780 (or 7778 counting only the distinct ones).

The product of its digits is 64, while the sum is 17.

The square root of 1821212 is about 1349.5228786501. The cubic root of 1821212 is about 122.1200109046.

Adding to 1821212 its reverse (2121281), we get a palindrome (3942493).

The spelling of 1821212 in words is "one million, eight hundred twenty-one thousand, two hundred twelve".