13213821 has 8 divisors (see below), whose sum is σ = 18226080. Its totient is φ = 8505392.

The previous prime is 13213769. The next prime is 13213829. The reversal of 13213821 is 12831231.

13213821 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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 13213821 - 2¹⁵ = 13181053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13213829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75855 + ... + 76028.

It is an arithmetic number, because the mean of its divisors is an integer number (2278260).

Almost surely, 2^13213821 is an apocalyptic number.

It is an amenable number.

13213821 is a deficient number, since it is larger than the sum of its proper divisors (5012259).

13213821 is a wasteful number, since it uses less digits than its factorization.

13213821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151915.

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

The square root of 13213821 is about 3635.0819798183. The cubic root of 13213821 is about 236.4156051723.

The spelling of 13213821 in words is "thirteen million, two hundred thirteen thousand, eight hundred twenty-one".