21533452 has 6 divisors (see below), whose sum is σ = 37683548. Its totient is φ = 10766724.

The previous prime is 21533443. The next prime is 21533459. The reversal of 21533452 is 25433512.

It is not an unprimeable number, because it can be changed into a prime (21533459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2691678 + ... + 2691685.

Almost surely, 2^21533452 is an apocalyptic number.

It is an amenable number.

21533452 is a deficient number, since it is larger than the sum of its proper divisors (16150096).

21533452 is a wasteful number, since it uses less digits than its factorization.

21533452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5383367 (or 5383365 counting only the distinct ones).

The product of its digits is 3600, while the sum is 25.

The square root of 21533452 is about 4640.4150676421. The cubic root of 21533452 is about 278.2090279625.

Adding to 21533452 its reverse (25433512), we get a palindrome (46966964).

The spelling of 21533452 in words is "twenty-one million, five hundred thirty-three thousand, four hundred fifty-two".