21210110221999 has 4 divisors (see below), whose sum is σ = 21448426067280. Its totient is φ = 20971794376720.

The previous prime is 21210110221981. The next prime is 21210110222009. The reversal of 21210110221999 is 99912201101212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210110221999 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 (21210110222999) 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, 119157922507 + ... + 119157922684.

It is an arithmetic number, because the mean of its divisors is an integer number (5362106516820).

Almost surely, 2^{21210110221999} is an apocalyptic number.

21210110221999 is a deficient number, since it is larger than the sum of its proper divisors (238315845281).

21210110221999 is an equidigital number, since it uses as much as digits as its factorization.

21210110221999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238315845280.

The product of its (nonzero) digits is 11664, while the sum is 40.

The spelling of 21210110221999 in words is "twenty-one trillion, two hundred ten billion, one hundred ten million, two hundred twenty-one thousand, nine hundred ninety-nine".