21004042112 has 32 divisors (see below), whose sum is σ = 42149455920. Its totient is φ = 10425355264.

The previous prime is 21004042061. The next prime is 21004042183. The reversal of 21004042112 is 21124040012.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 581348 + ... + 616419.

Almost surely, 2^21004042112 is an apocalyptic number.

It is an amenable number.

21004042112 is an abundant number, since it is smaller than the sum of its proper divisors (21145413808).

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

21004042112 is a wasteful number, since it uses less digits than its factorization.

21004042112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197918 (or 1197906 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21004042112 its reverse (21124040012), we get a palindrome (42128082124).

The spelling of 21004042112 in words is "twenty-one billion, four million, forty-two thousand, one hundred twelve".