21717132 has 24 divisors (see below), whose sum is σ = 50941296. Its totient is φ = 7200768.

The previous prime is 21717119. The next prime is 21717139. The reversal of 21717132 is 23171712.

It is not an unprimeable number, because it can be changed into a prime (21717139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2373 + ... + 7004.

It is an arithmetic number, because the mean of its divisors is an integer number (2122554).

Almost surely, 2^21717132 is an apocalyptic number.

It is an amenable number.

21717132 is an abundant number, since it is smaller than the sum of its proper divisors (29224164).

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

21717132 is a wasteful number, since it uses less digits than its factorization.

21717132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9577 (or 9575 counting only the distinct ones).

The product of its digits is 588, while the sum is 24.

The square root of 21717132 is about 4660.1643747834. The cubic root of 21717132 is about 278.9978288908.

Adding to 21717132 its reverse (23171712), we get a palindrome (44888844).

The spelling of 21717132 in words is "twenty-one million, seven hundred seventeen thousand, one hundred thirty-two".