21002104242 has 24 divisors (see below), whose sum is σ = 52005210816. Its totient is φ = 6000601176.

The previous prime is 21002104237. The next prime is 21002104261. The reversal of 21002104242 is 24240120012.

21002104242 is a `hidden beast` number, since 210 + 0 + 210 + 4 + 242 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83341558 + ... + 83341809.

It is an arithmetic number, because the mean of its divisors is an integer number (2166883784).

Almost surely, 2^21002104242 is an apocalyptic number.

21002104242 is an abundant number, since it is smaller than the sum of its proper divisors (31003106574).

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

21002104242 is a wasteful number, since it uses less digits than its factorization.

21002104242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166683382 (or 166683379 counting only the distinct ones).

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

Adding to 21002104242 its reverse (24240120012), we get a palindrome (45242224254).

The spelling of 21002104242 in words is "twenty-one billion, two million, one hundred four thousand, two hundred forty-two".