21271369 has 16 divisors (see below), whose sum is σ = 26345088. Its totient is φ = 16756992.

The previous prime is 21271351. The next prime is 21271379. The reversal of 21271369 is 96317212.

It is not a de Polignac number, because 21271369 - 2¹¹ = 21269321 is a prime.

It is a super-2 number, since 2×21271369² = 904942278268322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21271369.

It is not an unprimeable number, because it can be changed into a prime (21271319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3039 + ... + 7195.

It is an arithmetic number, because the mean of its divisors is an integer number (1646568).

Almost surely, 2^21271369 is an apocalyptic number.

It is an amenable number.

21271369 is a deficient number, since it is larger than the sum of its proper divisors (5073719).

21271369 is a wasteful number, since it uses less digits than its factorization.

21271369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4224.

The product of its digits is 4536, while the sum is 31.

The square root of 21271369 is about 4612.0894397225. The cubic root of 21271369 is about 277.0757264059.

The spelling of 21271369 in words is "twenty-one million, two hundred seventy-one thousand, three hundred sixty-nine".