21002122242 has 24 divisors (see below), whose sum is σ = 45507316140. Its totient is φ = 7000289280.

The previous prime is 21002122223. The next prime is 21002122243. The reversal of 21002122242 is 24222120012.

21002122242 is a `hidden beast` number, since 210 + 0 + 212 + 2 + 242 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17529495201 + 3472627041 = 132399^2 + 58929^2 .

It is a super-2 number, since 2×21002122242² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21002122243) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 482434 + ... + 524162.

Almost surely, 2^21002122242 is an apocalyptic number.

21002122242 is an abundant number, since it is smaller than the sum of its proper divisors (24505193898).

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

21002122242 is a wasteful number, since it uses less digits than its factorization.

21002122242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69698 (or 69695 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21002122242 its reverse (24222120012), we get a palindrome (45224242254).

The spelling of 21002122242 in words is "twenty-one billion, two million, one hundred twenty-two thousand, two hundred forty-two".