21727232 has 36 divisors (see below), whose sum is σ = 43869735. Its totient is φ = 10758144.

The previous prime is 21727231. The next prime is 21727247. The reversal of 21727232 is 23272712.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 10863616 + 10863616 = 3296^2 + 3296^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3296.

It is a super-2 number, since 2×21727232² = 944145220763648, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21727231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 210893 + ... + 210995.

Almost surely, 2^21727232 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 21727232

21727232 is an abundant number, since it is smaller than the sum of its proper divisors (22142503).

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

21727232 is an frugal number, since it uses more digits than its factorization.

21727232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 105 counting only the distinct ones).

The product of its digits is 2352, while the sum is 26.

The square root of 21727232 is about 4661.2479015817. The cubic root of 21727232 is about 279.0410734184.

Adding to 21727232 its reverse (23272712), we get a palindrome (44999944).

The spelling of 21727232 in words is "twenty-one million, seven hundred twenty-seven thousand, two hundred thirty-two".