21236253 has 8 divisors (see below), whose sum is σ = 28737888. Its totient is φ = 13946064.

The previous prime is 21236251. The next prime is 21236263. The reversal of 21236253 is 35263212.

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

It is not a de Polignac number, because 21236253 - 2¹ = 21236251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21236251) 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, 52626 + ... + 53027.

It is an arithmetic number, because the mean of its divisors is an integer number (3592236).

Almost surely, 2^21236253 is an apocalyptic number.

It is an amenable number.

21236253 is a deficient number, since it is larger than the sum of its proper divisors (7501635).

21236253 is a wasteful number, since it uses less digits than its factorization.

21236253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105723.

The product of its digits is 2160, while the sum is 24.

The square root of 21236253 is about 4608.2809159165. The cubic root of 21236253 is about 276.9231715752.

Adding to 21236253 its reverse (35263212), we get a palindrome (56499465).

The spelling of 21236253 in words is "twenty-one million, two hundred thirty-six thousand, two hundred fifty-three".