21001199999 has 8 divisors (see below), whose sum is σ = 22768468800. Its totient is φ = 19255615776.

The previous prime is 21001199993. The next prime is 21001200001. The reversal of 21001199999 is 99999110012.

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

It is a cyclic number.

It is not a de Polignac number, because 21001199999 - 2²⁰ = 21000151423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001199993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5419127 + ... + 5423000.

It is an arithmetic number, because the mean of its divisors is an integer number (2846058600).

Almost surely, 2^21001199999 is an apocalyptic number.

21001199999 is a deficient number, since it is larger than the sum of its proper divisors (1767268801).

21001199999 is a wasteful number, since it uses less digits than its factorization.

21001199999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10842289.

The product of its (nonzero) digits is 118098, while the sum is 50.

The spelling of 21001199999 in words is "twenty-one billion, one million, one hundred ninety-nine thousand, nine hundred ninety-nine".