1821612 has 24 divisors (see below), whose sum is σ = 4577776. Its totient is φ = 560448.

The previous prime is 1821583. The next prime is 1821613. The reversal of 1821612 is 2161281.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1821613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5683 + ... + 5994.

2^1821612 is an apocalyptic number.

1821612 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1821612 is an abundant number, since it is smaller than the sum of its proper divisors (2756164).

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

1821612 is a wasteful number, since it uses less digits than its factorization.

1821612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11697 (or 11695 counting only the distinct ones).

The product of its digits is 192, while the sum is 21.

The square root of 1821612 is about 1349.6710710392. The cubic root of 1821612 is about 122.1289508173.

Adding to 1821612 its reverse (2161281), we get a palindrome (3982893).

The spelling of 1821612 in words is "one million, eight hundred twenty-one thousand, six hundred twelve".