21042452320 has 24 divisors (see below), whose sum is σ = 49712793984. Its totient is φ = 8416980864.

The previous prime is 21042452309. The next prime is 21042452323. The reversal of 21042452320 is 2325424012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042452323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65757504 + ... + 65757823.

It is an arithmetic number, because the mean of its divisors is an integer number (2071366416).

Almost surely, 2^21042452320 is an apocalyptic number.

21042452320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21042452320 is an abundant number, since it is smaller than the sum of its proper divisors (28670341664).

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

21042452320 is a wasteful number, since it uses less digits than its factorization.

21042452320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131515342 (or 131515334 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21042452320 its reverse (2325424012), we get a palindrome (23367876332).

The spelling of 21042452320 in words is "twenty-one billion, forty-two million, four hundred fifty-two thousand, three hundred twenty".