21272472 has 48 divisors (see below), whose sum is σ = 62047440. Its totient is φ = 6545088.

The previous prime is 21272453. The next prime is 21272473. The reversal of 21272472 is 27427212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10428 + ... + 12299.

It is an arithmetic number, because the mean of its divisors is an integer number (1292655).

Almost surely, 2^21272472 is an apocalyptic number.

It is an amenable number.

21272472 is an abundant number, since it is smaller than the sum of its proper divisors (40774968).

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

21272472 is a wasteful number, since it uses less digits than its factorization.

21272472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22752 (or 22745 counting only the distinct ones).

The product of its digits is 3136, while the sum is 27.

The square root of 21272472 is about 4612.2090152117. The cubic root of 21272472 is about 277.0805154606.

Adding to 21272472 its reverse (27427212), we get a palindrome (48699684).

The spelling of 21272472 in words is "twenty-one million, two hundred seventy-two thousand, four hundred seventy-two".