21124452 has 12 divisors (see below), whose sum is σ = 49290416. Its totient is φ = 7041480.

The previous prime is 21124391. The next prime is 21124459. The reversal of 21124452 is 25442112.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21124459) 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, 880174 + ... + 880197.

Almost surely, 2^21124452 is an apocalyptic number.

It is an amenable number.

21124452 is an abundant number, since it is smaller than the sum of its proper divisors (28165964).

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

21124452 is a wasteful number, since it uses less digits than its factorization.

21124452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760378 (or 1760376 counting only the distinct ones).

The product of its digits is 640, while the sum is 21.

The square root of 21124452 is about 4596.1344627850. The cubic root of 21124452 is about 276.4363503133.

Adding to 21124452 its reverse (25442112), we get a palindrome (46566564).

The spelling of 21124452 in words is "twenty-one million, one hundred twenty-four thousand, four hundred fifty-two".