21144551124 has 24 divisors (see below), whose sum is σ = 49931713440. Its totient is φ = 6963265504.

The previous prime is 21144551123. The next prime is 21144551189. The reversal of 21144551124 is 42115544112.

It is a junction number, because it is equal to n+sod(n) for n = 21144551091 and 21144551100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144551123) 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 7 ways as a sum of consecutive naturals, for example, 10613739 + ... + 10615730.

It is an arithmetic number, because the mean of its divisors is an integer number (2080488060).

Almost surely, 2^21144551124 is an apocalyptic number.

It is an amenable number.

21144551124 is an abundant number, since it is smaller than the sum of its proper divisors (28787162316).

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

21144551124 is a wasteful number, since it uses less digits than its factorization.

21144551124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21229559 (or 21229557 counting only the distinct ones).

The product of its digits is 6400, while the sum is 30.

The spelling of 21144551124 in words is "twenty-one billion, one hundred forty-four million, five hundred fifty-one thousand, one hundred twenty-four".