21253353 has 32 divisors (see below), whose sum is σ = 32182272. Its totient is φ = 12364800.

The previous prime is 21253339. The next prime is 21253361. The reversal of 21253353 is 35335212.

It is a happy number.

It is not a de Polignac number, because 21253353 - 2²⁴ = 4476137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21253313) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 110025 + ... + 110217.

It is an arithmetic number, because the mean of its divisors is an integer number (1005696).

Almost surely, 2^21253353 is an apocalyptic number.

It is an amenable number.

21253353 is a deficient number, since it is larger than the sum of its proper divisors (10928919).

21253353 is a wasteful number, since it uses less digits than its factorization.

21253353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325.

The product of its digits is 2700, while the sum is 24.

The square root of 21253353 is about 4610.1358982138. The cubic root of 21253353 is about 276.9974802866.

Adding to 21253353 its reverse (35335212), we get a palindrome (56588565).

The spelling of 21253353 in words is "twenty-one million, two hundred fifty-three thousand, three hundred fifty-three".