12821861 has 6 divisors (see below), whose sum is σ = 13884210. Its totient is φ = 11835408.

The previous prime is 12821843. The next prime is 12821891. The reversal of 12821861 is 16812821.

12821861 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 3 ways, for example, as 84100 + 12737761 = 290^2 + 3569^2 .

It is not a de Polignac number, because 12821861 - 2¹⁴ = 12805477 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 (12821801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37766 + ... + 38103.

It is an arithmetic number, because the mean of its divisors is an integer number (2314035).

Almost surely, 2^12821861 is an apocalyptic number.

It is an amenable number.

12821861 is a deficient number, since it is larger than the sum of its proper divisors (1062349).

12821861 is an equidigital number, since it uses as much as digits as its factorization.

12821861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75895 (or 75882 counting only the distinct ones).

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

The square root of 12821861 is about 3580.7626282679. The cubic root of 12821861 is about 234.0545140481.

The spelling of 12821861 in words is "twelve million, eight hundred twenty-one thousand, eight hundred sixty-one".