21204240042 has 8 divisors (see below), whose sum is σ = 42408480096. Its totient is φ = 7068080012.

The previous prime is 21204240037. The next prime is 21204240059. The reversal of 21204240042 is 24004240212.

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

21204240042 is an admirable number.

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, 1767019998 + ... + 1767020009.

It is an arithmetic number, because the mean of its divisors is an integer number (5301060012).

Almost surely, 2^21204240042 is an apocalyptic number.

21204240042 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21204240042 is a wasteful number, since it uses less digits than its factorization.

21204240042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3534040012.

The product of its (nonzero) digits is 1024, while the sum is 21.

Adding to 21204240042 its reverse (24004240212), we get a palindrome (45208480254).

The spelling of 21204240042 in words is "twenty-one billion, two hundred four million, two hundred forty thousand, forty-two".