22021213 has 4 divisors (see below), whose sum is σ = 22034908. Its totient is φ = 22007520.

The previous prime is 22021211. The next prime is 22021229. The reversal of 22021213 is 31212022.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8749764 + 13271449 = 2958^2 + 3643^2 .

It is a cyclic number.

It is not a de Polignac number, because 22021213 - 2¹ = 22021211 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22021193 and 22021202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021211) 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, 4056 + ... + 7777.

It is an arithmetic number, because the mean of its divisors is an integer number (5508727).

Almost surely, 2^22021213 is an apocalyptic number.

It is an amenable number.

22021213 is a deficient number, since it is larger than the sum of its proper divisors (13695).

22021213 is a wasteful number, since it uses less digits than its factorization.

22021213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13694.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 22021213 is about 4692.6765283791. The cubic root of 22021213 is about 280.2939642263.

Adding to 22021213 its reverse (31212022), we get a palindrome (53233235).

The spelling of 22021213 in words is "twenty-two million, twenty-one thousand, two hundred thirteen".