12861821 has 8 divisors (see below), whose sum is σ = 14751744. Its totient is φ = 10985040.

The previous prime is 12861817. The next prime is 12861847. The reversal of 12861821 is 12816821.

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 12861821 - 2² = 12861817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12861421) 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 7 ways as a sum of consecutive naturals, for example, 1085 + ... + 5186.

It is an arithmetic number, because the mean of its divisors is an integer number (1843968).

Almost surely, 2^12861821 is an apocalyptic number.

It is an amenable number.

12861821 is a deficient number, since it is larger than the sum of its proper divisors (1889923).

12861821 is an equidigital number, since it uses as much as digits as its factorization.

12861821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6571.

The product of its digits is 1536, while the sum is 29.

The square root of 12861821 is about 3586.3381045295. The cubic root of 12861821 is about 234.2974095993.

The spelling of 12861821 in words is "twelve million, eight hundred sixty-one thousand, eight hundred twenty-one".