21302275 has 12 divisors (see below), whose sum is σ = 27969192. Its totient is φ = 16039040.

The previous prime is 21302273. The next prime is 21302279. The reversal of 21302275 is 57220312.

It is not a de Polignac number, because 21302275 - 2¹ = 21302273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21302273) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24637 + ... + 25486.

It is an arithmetic number, because the mean of its divisors is an integer number (2330766).

Almost surely, 2^21302275 is an apocalyptic number.

21302275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21302275 is a deficient number, since it is larger than the sum of its proper divisors (6666917).

21302275 is a wasteful number, since it uses less digits than its factorization.

21302275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50150 (or 50145 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21302275 is about 4615.4387657080. The cubic root of 21302275 is about 277.2098528371.

Adding to 21302275 its reverse (57220312), we get a palindrome (78522587).

The spelling of 21302275 in words is "twenty-one million, three hundred two thousand, two hundred seventy-five".