22217621 has 4 divisors (see below), whose sum is σ = 22377600. Its totient is φ = 22057644.

The previous prime is 22217617. The next prime is 22217633. The reversal of 22217621 is 12671222.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 22217621 - 2² = 22217617 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 (22217641) 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 3 ways as a sum of consecutive naturals, for example, 79781 + ... + 80058.

It is an arithmetic number, because the mean of its divisors is an integer number (5594400).

Almost surely, 2^22217621 is an apocalyptic number.

It is an amenable number.

22217621 is a deficient number, since it is larger than the sum of its proper divisors (159979).

22217621 is a wasteful number, since it uses less digits than its factorization.

22217621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159978.

The product of its digits is 672, while the sum is 23.

The square root of 22217621 is about 4713.5571493300. The cubic root of 22217621 is about 281.1248163222.

Adding to 22217621 its reverse (12671222), we get a palindrome (34888843).

The spelling of 22217621 in words is "twenty-two million, two hundred seventeen thousand, six hundred twenty-one".