12910821 has 24 divisors (see below), whose sum is σ = 21628992. Its totient is φ = 6705600.

The previous prime is 12910819. The next prime is 12910867. The reversal of 12910821 is 12801921.

12910821 is a nontrivial binomial coefficient, being equal to C(5082, 2).

It is not a de Polignac number, because 12910821 - 2¹ = 12910819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12910791 and 12910800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12910801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1 + ... + 5081.

It is an arithmetic number, because the mean of its divisors is an integer number (901208).

Almost surely, 2^12910821 is an apocalyptic number.

12910821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12910821 is the 5081-st triangular number and also the 2541-st hexagonal number.

It is an amenable number.

12910821 is a deficient number, since it is larger than the sum of its proper divisors (8718171).

12910821 is a wasteful number, since it uses less digits than its factorization.

With its successor (12910822) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (5102).

12910821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5113 (or 5102 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 12910821 is about 3593.1630912053. The cubic root of 12910821 is about 234.5945687801.

Subtracting from 12910821 its reverse (12801921), we obtain a square (108900 = 330²).

It can be divided in two parts, 12910 and 821, that added together give a palindrome (13731).

The spelling of 12910821 in words is "twelve million, nine hundred ten thousand, eight hundred twenty-one".