21222505 has 8 divisors (see below), whose sum is σ = 25502400. Its totient is φ = 16954416.

The previous prime is 21222503. The next prime is 21222529. The reversal of 21222505 is 50522212.

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 21222505 - 2¹ = 21222503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21222503) 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, 1666 + ... + 6724.

It is an arithmetic number, because the mean of its divisors is an integer number (3187800).

Almost surely, 2^21222505 is an apocalyptic number.

It is an amenable number.

21222505 is a deficient number, since it is larger than the sum of its proper divisors (4279895).

21222505 is an equidigital number, since it uses as much as digits as its factorization.

21222505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5903.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21222505 is about 4606.7890118824. The cubic root of 21222505 is about 276.8634001768.

Adding to 21222505 its reverse (50522212), we get a palindrome (71744717).

The spelling of 21222505 in words is "twenty-one million, two hundred twenty-two thousand, five hundred five".