21036275 has 24 divisors (see below), whose sum is σ = 28331520. Its totient is φ = 15493920.

The previous prime is 21036271. The next prime is 21036289. The reversal of 21036275 is 57263012.

It is not a de Polignac number, because 21036275 - 2² = 21036271 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21036271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54734 + ... + 55116.

It is an arithmetic number, because the mean of its divisors is an integer number (1180480).

Almost surely, 2^21036275 is an apocalyptic number.

21036275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21036275 is a deficient number, since it is larger than the sum of its proper divisors (7295245).

21036275 is an equidigital number, since it uses as much as digits as its factorization.

21036275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 21036275 is about 4586.5319142027. The cubic root of 21036275 is about 276.0511833593.

Adding to 21036275 its reverse (57263012), we get a palindrome (78299287).

The spelling of 21036275 in words is "twenty-one million, thirty-six thousand, two hundred seventy-five".