21101212211999 has 4 divisors (see below), whose sum is σ = 22211802328440. Its totient is φ = 19990622095560.

The previous prime is 21101212211921. The next prime is 21101212212013. The reversal of 21101212211999 is 99911221210112.

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 21101212211999 - 2¹² = 21101212207903 is a prime.

It is a super-2 number, since 2×21101212211999² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101212211399) 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, 555295058192 + ... + 555295058229.

It is an arithmetic number, because the mean of its divisors is an integer number (5552950582110).

Almost surely, 2^{21101212211999} is an apocalyptic number.

21101212211999 is a deficient number, since it is larger than the sum of its proper divisors (1110590116441).

21101212211999 is a wasteful number, since it uses less digits than its factorization.

21101212211999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1110590116440.

The product of its (nonzero) digits is 11664, while the sum is 41.

The spelling of 21101212211999 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, two hundred eleven thousand, nine hundred ninety-nine".