21130275 has 12 divisors (see below), whose sum is σ = 34935512. Its totient is φ = 11269440.

The previous prime is 21130267. The next prime is 21130279. The reversal of 21130275 is 57203112.

It is not a de Polignac number, because 21130275 - 2³ = 21130267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21130279) 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, 140794 + ... + 140943.

Almost surely, 2^21130275 is an apocalyptic number.

21130275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21130275 is a deficient number, since it is larger than the sum of its proper divisors (13805237).

21130275 is a wasteful number, since it uses less digits than its factorization.

21130275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281750 (or 281745 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21130275 is about 4596.7678862436. The cubic root of 21130275 is about 276.4617480686.

Adding to 21130275 its reverse (57203112), we get a palindrome (78333387).

The spelling of 21130275 in words is "twenty-one million, one hundred thirty thousand, two hundred seventy-five".