21003840012 has 24 divisors (see below), whose sum is σ = 49494200112. Its totient is φ = 6931960000.

The previous prime is 21003840007. The next prime is 21003840029. The reversal of 21003840012 is 21004830012.

It is a super-2 number, since 2×21003840012² (a number of 21 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 8663739 + ... + 8666162.

It is an arithmetic number, because the mean of its divisors is an integer number (2062258338).

Almost surely, 2^21003840012 is an apocalyptic number.

It is an amenable number.

21003840012 is an abundant number, since it is smaller than the sum of its proper divisors (28490360100).

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

21003840012 is a wasteful number, since it uses less digits than its factorization.

21003840012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17330009 (or 17330007 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The spelling of 21003840012 in words is "twenty-one billion, three million, eight hundred forty thousand, twelve".