11211212101 has 4 divisors (see below), whose sum is σ = 11211993100.
Its totient is φ = 11210431104.
The previous prime is 11211212053. The next prime is 11211212123. The reversal of 11211212101 is 10121211211.
It is a happy number.
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 5623500100 + 5587712001 = 74990^2 + 74751^2
It is a cyclic number.
It is not a de Polignac number, because 11211212101 - 215 = 11211179333 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 (11211212191) 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, 368556 + ... + 397813.
It is an arithmetic number, because the mean of its divisors is an integer number (2802998275).
Almost surely, 211211212101 is an apocalyptic number.
It is an amenable number.
11211212101 is a deficient number, since it is larger than the sum of its proper divisors (780999).
11211212101 is an equidigital number, since it uses as much as digits as its factorization.
11211212101 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 780998.
The product of its (nonzero) digits is 8, while the sum is 13.
Adding to 11211212101 its reverse (10121211211), we get a palindrome (21332423312).
It can be divided in two parts, 11 and 211212101, that added together give a palindrome (211212112).
The spelling of 11211212101 in words is "eleven billion, two hundred eleven million, two hundred twelve thousand, one hundred one".