21224151 has 24 divisors (see below), whose sum is σ = 33183696. Its totient is φ = 12994560.

The previous prime is 21224149. The next prime is 21224167. The reversal of 21224151 is 15142212.

It is not a de Polignac number, because 21224151 - 2¹ = 21224149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32791 + ... + 33431.

It is an arithmetic number, because the mean of its divisors is an integer number (1382654).

Almost surely, 2^21224151 is an apocalyptic number.

21224151 is a deficient number, since it is larger than the sum of its proper divisors (11959545).

21224151 is a wasteful number, since it uses less digits than its factorization.

21224151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 943 (or 940 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21224151 is about 4606.9676577983. The cubic root of 21224151 is about 276.8705577575.

Adding to 21224151 its reverse (15142212), we get a palindrome (36366363).

The spelling of 21224151 in words is "twenty-one million, two hundred twenty-four thousand, one hundred fifty-one".