21209332 has 12 divisors (see below), whose sum is σ = 38313856. Its totient is φ = 10262520.

The previous prime is 21209327. The next prime is 21209359. The reversal of 21209332 is 23390212.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 85398 + ... + 85645.

Almost surely, 2^21209332 is an apocalyptic number.

It is an amenable number.

21209332 is a deficient number, since it is larger than the sum of its proper divisors (17104524).

21209332 is a wasteful number, since it uses less digits than its factorization.

21209332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171078 (or 171076 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21209332 is about 4605.3590522347. The cubic root of 21209332 is about 276.8061044518.

Adding to 21209332 its reverse (23390212), we get a palindrome (44599544).

The spelling of 21209332 in words is "twenty-one million, two hundred nine thousand, three hundred thirty-two".