12018821 has 8 divisors (see below), whose sum is σ = 12428280. Its totient is φ = 11613888.

The previous prime is 12018817. The next prime is 12018833. The reversal of 12018821 is 12881021.

It is a happy number.

12018821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1221025 + 10797796 = 1105^2 + 3286^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 12018821 - 2² = 12018817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12018841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4775 + ... + 6843.

It is an arithmetic number, because the mean of its divisors is an integer number (1553535).

Almost surely, 2^12018821 is an apocalyptic number.

It is an amenable number.

12018821 is a deficient number, since it is larger than the sum of its proper divisors (409459).

12018821 is a wasteful number, since it uses less digits than its factorization.

12018821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2263.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 12018821 is about 3466.8171281451. The cubic root of 12018821 is about 229.0624785823.

Adding to 12018821 its reverse (12881021), we get a palindrome (24899842).

The spelling of 12018821 in words is "twelve million, eighteen thousand, eight hundred twenty-one".