21356271 has 16 divisors (see below), whose sum is σ = 31737600. Its totient is φ = 14193144.

The previous prime is 21356219. The next prime is 21356287. The reversal of 21356271 is 17265312.

It is a happy number.

21356271 is a `hidden beast` number, since 2 + 1 + 35 + 627 + 1 = 666.

It is not a de Polignac number, because 21356271 - 2⁶ = 21356207 is a prime.

It is a super-2 number, since 2×21356271² = 912180622050882, which contains 22 as substring.

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

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9190 + ... + 11276.

It is an arithmetic number, because the mean of its divisors is an integer number (1983600).

Almost surely, 2^21356271 is an apocalyptic number.

21356271 is a deficient number, since it is larger than the sum of its proper divisors (10381329).

21356271 is a wasteful number, since it uses less digits than its factorization.

21356271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2475 (or 2469 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 21356271 is about 4621.2845616776. The cubic root of 21356271 is about 277.4438746974.

The spelling of 21356271 in words is "twenty-one million, three hundred fifty-six thousand, two hundred seventy-one".