21362253 has 8 divisors (see below), whose sum is σ = 31072416. Its totient is φ = 12946800.

The previous prime is 21362227. The next prime is 21362269. The reversal of 21362253 is 35226312.

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

It is not a de Polignac number, because 21362253 - 2¹⁰ = 21361229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21362203) 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, 323638 + ... + 323703.

It is an arithmetic number, because the mean of its divisors is an integer number (3884052).

Almost surely, 2^21362253 is an apocalyptic number.

It is an amenable number.

21362253 is a deficient number, since it is larger than the sum of its proper divisors (9710163).

21362253 is a wasteful number, since it uses less digits than its factorization.

21362253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647355.

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

The square root of 21362253 is about 4621.9317390026. The cubic root of 21362253 is about 277.4697767587.

Adding to 21362253 its reverse (35226312), we get a palindrome (56588565).

The spelling of 21362253 in words is "twenty-one million, three hundred sixty-two thousand, two hundred fifty-three".