21224230253 has 4 divisors (see below), whose sum is σ = 21238562748. Its totient is φ = 21209897760.

The previous prime is 21224230241. The next prime is 21224230267. The reversal of 21224230253 is 35203242212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13958713609 + 7265516644 = 118147^2 + 85238^2 .

It is a cyclic number.

It is not a de Polignac number, because 21224230253 - 2⁸ = 21224229997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224230213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7164026 + ... + 7166987.

It is an arithmetic number, because the mean of its divisors is an integer number (5309640687).

Almost surely, 2^21224230253 is an apocalyptic number.

It is an amenable number.

21224230253 is a deficient number, since it is larger than the sum of its proper divisors (14332495).

21224230253 is a wasteful number, since it uses less digits than its factorization.

21224230253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14332494.

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 21224230253 its reverse (35203242212), we get a palindrome (56427472465).

The spelling of 21224230253 in words is "twenty-one billion, two hundred twenty-four million, two hundred thirty thousand, two hundred fifty-three".