21224051 has 8 divisors (see below), whose sum is σ = 21876144. Its totient is φ = 20576160.

The previous prime is 21224023. The next prime is 21224053. The reversal of 21224051 is 15042212.

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 21224051 - 2¹⁸ = 20961907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21224053) 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, 11381 + ... + 13113.

It is an arithmetic number, because the mean of its divisors is an integer number (2734518).

Almost surely, 2^21224051 is an apocalyptic number.

21224051 is a deficient number, since it is larger than the sum of its proper divisors (652093).

21224051 is a wasteful number, since it uses less digits than its factorization.

21224051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101.

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

The square root of 21224051 is about 4606.9568046597. The cubic root of 21224051 is about 276.8701229211.

Adding to 21224051 its reverse (15042212), we get a palindrome (36266263).

The spelling of 21224051 in words is "twenty-one million, two hundred twenty-four thousand, fifty-one".