21532472 has 64 divisors (see below), whose sum is σ = 48535200. Its totient is φ = 8847360.

The previous prime is 21532417. The next prime is 21532499. The reversal of 21532472 is 27423512.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a plaindrome in base 9.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 33272 + ... + 33912.

Almost surely, 2^21532472 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 21532472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24267600).

21532472 is an abundant number, since it is smaller than the sum of its proper divisors (27002728).

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

21532472 is a wasteful number, since it uses less digits than its factorization.

21532472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696 (or 692 counting only the distinct ones).

The product of its digits is 3360, while the sum is 26.

The square root of 21532472 is about 4640.3094724382. The cubic root of 21532472 is about 278.2048074133.

Adding to 21532472 its reverse (27423512), we get a palindrome (48955984).

The spelling of 21532472 in words is "twenty-one million, five hundred thirty-two thousand, four hundred seventy-two".