21711132 has 48 divisors (see below), whose sum is σ = 57365280. Its totient is φ = 7098624.

The previous prime is 21711127. The next prime is 21711143. The reversal of 21711132 is 23111712.

It is a happy number.

It is a super-3 number, since 3×21711132³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 3828 + ... + 7620.

It is an arithmetic number, because the mean of its divisors is an integer number (1195110).

Almost surely, 2^21711132 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 21711132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28682640).

21711132 is an abundant number, since it is smaller than the sum of its proper divisors (35654148).

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

21711132 is a wasteful number, since it uses less digits than its factorization.

21711132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3859 (or 3851 counting only the distinct ones).

The product of its digits is 84, while the sum is 18.

The square root of 21711132 is about 4659.5205761967. The cubic root of 21711132 is about 278.9721327236.

Adding to 21711132 its reverse (23111712), we get a palindrome (44822844).

The spelling of 21711132 in words is "twenty-one million, seven hundred eleven thousand, one hundred thirty-two".