21210332 has 36 divisors (see below), whose sum is σ = 43950648. Its totient is φ = 8896800.

The previous prime is 21210317. The next prime is 21210337. The reversal of 21210332 is 23301212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4607 + ... + 7977.

Almost surely, 2^21210332 is an apocalyptic number.

21210332 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21210332 is an abundant number, since it is smaller than the sum of its proper divisors (22740316).

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

21210332 is a wasteful number, since it uses less digits than its factorization.

21210332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410 (or 3397 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21210332 is about 4605.4676201228. The cubic root of 21210332 is about 276.8104547657.

Adding to 21210332 its reverse (23301212), we get a palindrome (44511544).

The spelling of 21210332 in words is "twenty-one million, two hundred ten thousand, three hundred thirty-two".