21126275 has 12 divisors (see below), whose sum is σ = 26836824. Its totient is φ = 16488000.

The previous prime is 21126253. The next prime is 21126289. The reversal of 21126275 is 57262112.

It is a de Polignac number, because none of the positive numbers 2^k-21126275 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9281 + ... + 11330.

It is an arithmetic number, because the mean of its divisors is an integer number (2236402).

Almost surely, 2^21126275 is an apocalyptic number.

21126275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21126275 is a deficient number, since it is larger than the sum of its proper divisors (5710549).

21126275 is a wasteful number, since it uses less digits than its factorization.

21126275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20662 (or 20657 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 21126275 is about 4596.3327773346. The cubic root of 21126275 is about 276.4443020615. Note that the first 3 decimals are identical.

Adding to 21126275 its reverse (57262112), we get a palindrome (78388387).

The spelling of 21126275 in words is "twenty-one million, one hundred twenty-six thousand, two hundred seventy-five".