21224706 has 16 divisors (see below), whose sum is σ = 43146048. Its totient is φ = 6958800.

The previous prime is 21224689. The next prime is 21224737. The reversal of 21224706 is 60742212.

It is an unprimeable number.

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, 28630 + ... + 29361.

It is an arithmetic number, because the mean of its divisors is an integer number (2696628).

Almost surely, 2^21224706 is an apocalyptic number.

21224706 is an abundant number, since it is smaller than the sum of its proper divisors (21921342).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21224706 is a wasteful number, since it uses less digits than its factorization.

21224706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58057.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21224706 is about 4607.0278922533. The cubic root of 21224706 is about 276.8729710746.

Adding to 21224706 its reverse (60742212), we get a palindrome (81966918).

The spelling of 21224706 in words is "twenty-one million, two hundred twenty-four thousand, seven hundred six".