21000332 has 12 divisors (see below), whose sum is σ = 36888096. Its totient is φ = 10460880.

The previous prime is 21000313. The next prime is 21000337. The reversal of 21000332 is 23300012.

It is a super-2 number, since 2×21000332² = 882027888220448, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21000337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8603 + ... + 10770.

It is an arithmetic number, because the mean of its divisors is an integer number (3074008).

Almost surely, 2^21000332 is an apocalyptic number.

It is an amenable number.

21000332 is a deficient number, since it is larger than the sum of its proper divisors (15887764).

21000332 is a wasteful number, since it uses less digits than its factorization.

21000332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19648 (or 19646 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 11.

The square root of 21000332 is about 4582.6119189824. The cubic root of 21000332 is about 275.8938715397.

Adding to 21000332 its reverse (23300012), we get a palindrome (44300344).

The spelling of 21000332 in words is "twenty-one million, three hundred thirty-two", and thus it is an aban number.