21124253532 has 12 divisors (see below), whose sum is σ = 49289924936. Its totient is φ = 7041417840.

The previous prime is 21124253531. The next prime is 21124253539. The reversal of 21124253532 is 23535242112.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21124253532.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124253531) 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, 880177219 + ... + 880177242.

Almost surely, 2^21124253532 is an apocalyptic number.

It is an amenable number.

21124253532 is an abundant number, since it is smaller than the sum of its proper divisors (28165671404).

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

21124253532 is a wasteful number, since it uses less digits than its factorization.

21124253532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760354468 (or 1760354466 counting only the distinct ones).

The product of its digits is 14400, while the sum is 30.

Adding to 21124253532 its reverse (23535242112), we get a palindrome (44659495644).

The spelling of 21124253532 in words is "twenty-one billion, one hundred twenty-four million, two hundred fifty-three thousand, five hundred thirty-two".