21271275 has 24 divisors (see below), whose sum is σ = 39077360. Its totient is φ = 11344320.

The previous prime is 21271259. The next prime is 21271277. The reversal of 21271275 is 57217212.

It is not a de Polignac number, because 21271275 - 2⁴ = 21271259 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21271277) 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, 15082 + ... + 16431.

Almost surely, 2^21271275 is an apocalyptic number.

21271275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21271275 is a deficient number, since it is larger than the sum of its proper divisors (17806085).

21271275 is a wasteful number, since it uses less digits than its factorization.

21271275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31532 (or 31521 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 21271275 is about 4612.0792491023. The cubic root of 21271275 is about 277.0753182649.

Adding to 21271275 its reverse (57217212), we get a palindrome (78488487).

The spelling of 21271275 in words is "twenty-one million, two hundred seventy-one thousand, two hundred seventy-five".