21242221120 has 56 divisors (see below), whose sum is σ = 50709487608. Its totient is φ = 8475648000.

The previous prime is 21242221093. The next prime is 21242221127. The reversal of 21242221120 is 2112224212.

It can be written as a sum of positive squares in 4 ways, for example, as 3153047104 + 18089174016 = 56152^2 + 134496^2 .

It is a super-2 number, since 2×21242221120² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21242221127) 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, 45550 + ... + 211090.

Almost surely, 2^21242221120 is an apocalyptic number.

21242221120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21242221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25354743804).

21242221120 is an abundant number, since it is smaller than the sum of its proper divisors (29467266488).

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

21242221120 is a wasteful number, since it uses less digits than its factorization.

21242221120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165959 (or 165949 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21242221120 its reverse (2112224212), we get a palindrome (23354445332).

The spelling of 21242221120 in words is "twenty-one billion, two hundred forty-two million, two hundred twenty-one thousand, one hundred twenty".