21000210109999 has 4 divisors (see below), whose sum is σ = 21016629352960. Its totient is φ = 20983790867040.

The previous prime is 21000210109981. The next prime is 21000210110027. The reversal of 21000210109999 is 99990101200012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21000210109999 - 2¹⁹ = 21000209585711 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 (21000210109919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8209619562 + ... + 8209622119.

It is an arithmetic number, because the mean of its divisors is an integer number (5254157338240).

Almost surely, 2^{21000210109999} is an apocalyptic number.

21000210109999 is a deficient number, since it is larger than the sum of its proper divisors (16419242961).

21000210109999 is a wasteful number, since it uses less digits than its factorization.

21000210109999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16419242960.

The product of its (nonzero) digits is 26244, while the sum is 43.

The spelling of 21000210109999 in words is "twenty-one trillion, two hundred ten million, one hundred nine thousand, nine hundred ninety-nine".