21001200009999 has 8 divisors (see below), whose sum is σ = 30547200014592. Its totient is φ = 12728000006040.

The previous prime is 21001200009991. The next prime is 21001200010001. The reversal of 21001200009999 is 99990000210012.

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

It is not a de Polignac number, because 21001200009999 - 2³ = 21001200009991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21001200009999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001200009991) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 318200000119 + ... + 318200000184.

It is an arithmetic number, because the mean of its divisors is an integer number (3818400001824).

Almost surely, 2^{21001200009999} is an apocalyptic number.

21001200009999 is a deficient number, since it is larger than the sum of its proper divisors (9546000004593).

21001200009999 is a wasteful number, since it uses less digits than its factorization.

21001200009999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636400000317.

The product of its (nonzero) digits is 26244, while the sum is 42.

The spelling of 21001200009999 in words is "twenty-one trillion, one billion, two hundred million, nine thousand, nine hundred ninety-nine".