21316272 has 20 divisors (see below), whose sum is σ = 55067160. Its totient is φ = 7105408.

The previous prime is 21316237. The next prime is 21316277. The reversal of 21316272 is 27261312.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21316277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221997 + ... + 222092.

It is an arithmetic number, because the mean of its divisors is an integer number (2753358).

Almost surely, 2^21316272 is an apocalyptic number.

It is an amenable number.

21316272 is an abundant number, since it is smaller than the sum of its proper divisors (33750888).

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

21316272 is a wasteful number, since it uses less digits than its factorization.

21316272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444100 (or 444094 counting only the distinct ones).

The product of its digits is 1008, while the sum is 24.

The square root of 21316272 is about 4616.9548405849. The cubic root of 21316272 is about 277.2705545977.

Adding to 21316272 its reverse (27261312), we get a palindrome (48577584).

The spelling of 21316272 in words is "twenty-one million, three hundred sixteen thousand, two hundred seventy-two".