21144542052 has 24 divisors (see below), whose sum is σ = 49471709056. Its totient is φ = 7028974368.

The previous prime is 21144542011. The next prime is 21144542059. The reversal of 21144542052 is 25024544112.

It is not an unprimeable number, because it can be changed into a prime (21144542059) 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, 2396203 + ... + 2405010.

Almost surely, 2^21144542052 is an apocalyptic number.

It is an amenable number.

21144542052 is an abundant number, since it is smaller than the sum of its proper divisors (28327167004).

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

21144542052 is a wasteful number, since it uses less digits than its factorization.

21144542052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4801587 (or 4801585 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 30.

The spelling of 21144542052 in words is "twenty-one billion, one hundred forty-four million, five hundred forty-two thousand, fifty-two".