13006821 has 4 divisors (see below), whose sum is σ = 17342432. Its totient is φ = 8671212.

The previous prime is 13006817. The next prime is 13006831. The reversal of 13006821 is 12860031.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12860031 = 3 ⋅4286677.

It is not a de Polignac number, because 13006821 - 2² = 13006817 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 (13006831) 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, 2167801 + ... + 2167806.

It is an arithmetic number, because the mean of its divisors is an integer number (4335608).

Almost surely, 2^13006821 is an apocalyptic number.

It is an amenable number.

13006821 is a deficient number, since it is larger than the sum of its proper divisors (4335611).

13006821 is an equidigital number, since it uses as much as digits as its factorization.

13006821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4335610.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 13006821 is about 3606.4970539292. The cubic root of 13006821 is about 235.1745858224.

Adding to 13006821 its reverse (12860031), we get a palindrome (25866852).

The spelling of 13006821 in words is "thirteen million, six thousand, eight hundred twenty-one".