21204220042 has 8 divisors (see below), whose sum is σ = 32115129696. Its totient is φ = 10499176812.

The previous prime is 21204220013. The next prime is 21204220057. The reversal of 21204220042 is 24002240212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51466348 + ... + 51466759.

It is an arithmetic number, because the mean of its divisors is an integer number (4014391212).

Almost surely, 2^21204220042 is an apocalyptic number.

21204220042 is a deficient number, since it is larger than the sum of its proper divisors (10910909654).

21204220042 is a wasteful number, since it uses less digits than its factorization.

21204220042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102933212.

The product of its (nonzero) digits is 512, while the sum is 19.

Adding to 21204220042 its reverse (24002240212), we get a palindrome (45206460254).

The spelling of 21204220042 in words is "twenty-one billion, two hundred four million, two hundred twenty thousand, forty-two".