21042532 has 24 divisors (see below), whose sum is σ = 44561664. Its totient is φ = 8487552.

The previous prime is 21042491. The next prime is 21042533. The reversal of 21042532 is 23524012.

It is not an unprimeable number, because it can be changed into a prime (21042533) 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, 21628 + ... + 22579.

It is an arithmetic number, because the mean of its divisors is an integer number (1856736).

Almost surely, 2^21042532 is an apocalyptic number.

It is an amenable number.

21042532 is an abundant number, since it is smaller than the sum of its proper divisors (23519132).

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

21042532 is a wasteful number, since it uses less digits than its factorization.

21042532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44235 (or 44233 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21042532 is about 4587.2139692846. The cubic root of 21042532 is about 276.0785500712.

Adding to 21042532 its reverse (23524012), we get a palindrome (44566544).

The spelling of 21042532 in words is "twenty-one million, forty-two thousand, five hundred thirty-two".