22221521 has 8 divisors (see below), whose sum is σ = 25549440. Its totient is φ = 18931968.

The previous prime is 22221517. The next prime is 22221523. The reversal of 22221521 is 12512222.

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 22221521 - 2² = 22221517 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22221521.

It is not an unprimeable number, because it can be changed into a prime (22221523) 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 7 ways as a sum of consecutive naturals, for example, 8336 + ... + 10673.

It is an arithmetic number, because the mean of its divisors is an integer number (3193680).

Almost surely, 2^22221521 is an apocalyptic number.

It is an amenable number.

22221521 is a deficient number, since it is larger than the sum of its proper divisors (3327919).

22221521 is a wasteful number, since it uses less digits than its factorization.

22221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19183.

The product of its digits is 160, while the sum is 17.

The square root of 22221521 is about 4713.9708314753. The cubic root of 22221521 is about 281.1412645675.

Adding to 22221521 its reverse (12512222), we get a palindrome (34733743).

The spelling of 22221521 in words is "twenty-two million, two hundred twenty-one thousand, five hundred twenty-one".