21272 has 8 divisors (see below), whose sum is σ = 39900. Its totient is φ = 10632.

The previous prime is 21269. The next prime is 21277. The reversal of 21272 is 27212.

It is a tau number, because it is divible by the number of its divisors (8).

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322 + ... + 1337.

2²¹²⁷² is an apocalyptic number.

It is an amenable number.

21272 is a deficient number, since it is larger than the sum of its proper divisors (18628).

21272 is a wasteful number, since it uses less digits than its factorization.

21272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2665 (or 2661 counting only the distinct ones).

The product of its digits is 56, while the sum is 14.

The square root of 21272 is about 145.8492372280. The cubic root of 21272 is about 27.7078466130.

Adding to 21272 its reverse (27212), we get a palindrome (48484).

The spelling of 21272 in words is "twenty-one thousand, two hundred seventy-two", and thus it is an iban number.