13216021 has 16 divisors (see below), whose sum is σ = 17224704. Its totient is φ = 9840384.

The previous prime is 13216009. The next prime is 13216031. The reversal of 13216021 is 12061231.

It is a cyclic number.

It is not a de Polignac number, because 13216021 - 2⁷ = 13215893 is a prime.

It is a super-2 number, since 2×13216021² = 349326422144882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 13215986 and 13216004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13216031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2725 + ... + 5818.

It is an arithmetic number, because the mean of its divisors is an integer number (1076544).

Almost surely, 2^13216021 is an apocalyptic number.

It is an amenable number.

13216021 is a deficient number, since it is larger than the sum of its proper divisors (4008683).

13216021 is a wasteful number, since it uses less digits than its factorization.

13216021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8580.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 13216021 is about 3635.3845738794. The cubic root of 13216021 is about 236.4287249068.

Adding to 13216021 its reverse (12061231), we get a palindrome (25277252).

The spelling of 13216021 in words is "thirteen million, two hundred sixteen thousand, twenty-one".