21267272 has 64 divisors (see below), whose sum is σ = 47537280. Its totient is φ = 8819712.

The previous prime is 21267263. The next prime is 21267371. The reversal of 21267272 is 27276212.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40403 + ... + 40925.

It is an arithmetic number, because the mean of its divisors is an integer number (742770).

Almost surely, 2^21267272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21267272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23768640).

21267272 is an abundant number, since it is smaller than the sum of its proper divisors (26270008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21267272 is a wasteful number, since it uses less digits than its factorization.

21267272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582 (or 578 counting only the distinct ones).

The product of its digits is 4704, while the sum is 29.

The square root of 21267272 is about 4611.6452595576. The cubic root of 21267272 is about 277.0579364189.

The spelling of 21267272 in words is "twenty-one million, two hundred sixty-seven thousand, two hundred seventy-two".