21224506 has 8 divisors (see below), whose sum is σ = 31940064. Its totient is φ = 10577820.

The previous prime is 21224503. The next prime is 21224509. The reversal of 21224506 is 60542212.

It is an interprime number because it is at equal distance from previous prime (21224503) and next prime (21224509).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21224503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16440 + ... + 17683.

It is an arithmetic number, because the mean of its divisors is an integer number (3992508).

Almost surely, 2^21224506 is an apocalyptic number.

21224506 is a deficient number, since it is larger than the sum of its proper divisors (10715558).

21224506 is a wasteful number, since it uses less digits than its factorization.

21224506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34436.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21224506 is about 4607.0061862342. The cubic root of 21224506 is about 276.8721014156.

Adding to 21224506 its reverse (60542212), we get a palindrome (81766718).

The spelling of 21224506 in words is "twenty-one million, two hundred twenty-four thousand, five hundred six".