21124344220 has 24 divisors (see below), whose sum is σ = 50698426464. Its totient is φ = 7242632256.

The previous prime is 21124344203. The next prime is 21124344221. The reversal of 21124344220 is 2244342112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124344221) 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, 75443947 + ... + 75444226.

It is an arithmetic number, because the mean of its divisors is an integer number (2112434436).

Almost surely, 2^21124344220 is an apocalyptic number.

21124344220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21124344220 is an abundant number, since it is smaller than the sum of its proper divisors (29574082244).

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

21124344220 is a wasteful number, since it uses less digits than its factorization.

21124344220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150888189 (or 150888187 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21124344220 its reverse (2244342112), we get a palindrome (23368686332).

The spelling of 21124344220 in words is "twenty-one billion, one hundred twenty-four million, three hundred forty-four thousand, two hundred twenty".