12800821 has 4 divisors (see below), whose sum is σ = 13964544. Its totient is φ = 11637100.

The previous prime is 12800797. The next prime is 12800831.

12800821 is nontrivially palindromic in base 10.

12800821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12800821 is a prime.

It is a super-2 number, since 2×12800821² = 327722036548082, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 12800792 and 12800801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12800831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 581845 + ... + 581866.

It is an arithmetic number, because the mean of its divisors is an integer number (3491136).

Almost surely, 2^12800821 is an apocalyptic number.

12800821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12800821 is a deficient number, since it is larger than the sum of its proper divisors (1163723).

12800821 is a wasteful number, since it uses less digits than its factorization.

12800821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163722.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 12800821 is about 3577.8235003980. The cubic root of 12800821 is about 233.9264202388.

The spelling of 12800821 in words is "twelve million, eight hundred thousand, eight hundred twenty-one".