21121342242 has 128 divisors (see below), whose sum is σ = 56779204608. Its totient is φ = 5058547200.

The previous prime is 21121342217. The next prime is 21121342243. The reversal of 21121342242 is 24224312112.

It is a super-2 number, since 2×21121342242² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121342243) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9194038 + ... + 9196334.

It is an arithmetic number, because the mean of its divisors is an integer number (443587536).

Almost surely, 2^21121342242 is an apocalyptic number.

21121342242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121342242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28389602304).

21121342242 is an abundant number, since it is smaller than the sum of its proper divisors (35657862366).

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

21121342242 is a wasteful number, since it uses less digits than its factorization.

21121342242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864.

The product of its digits is 1536, while the sum is 24.

Adding to 21121342242 its reverse (24224312112), we get a palindrome (45345654354).

It can be divided in two parts, 21121 and 342242, that added together give a palindrome (363363).

The spelling of 21121342242 in words is "twenty-one billion, one hundred twenty-one million, three hundred forty-two thousand, two hundred forty-two".