21121311101 has 4 divisors (see below), whose sum is σ = 23041430304. Its totient is φ = 19201191900.

The previous prime is 21121311077. The next prime is 21121311109. The reversal of 21121311101 is 10111312112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21121311101 - 2²⁶ = 21054202237 is a prime.

It is a super-2 number, since 2×21121311101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121311109) 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, 960059585 + ... + 960059606.

It is an arithmetic number, because the mean of its divisors is an integer number (5760357576).

Almost surely, 2^21121311101 is an apocalyptic number.

It is an amenable number.

21121311101 is a deficient number, since it is larger than the sum of its proper divisors (1920119203).

21121311101 is a wasteful number, since it uses less digits than its factorization.

21121311101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1920119202.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21121311101 its reverse (10111312112), we get a palindrome (31232623213).

It can be divided in two parts, 211 and 21311101, that added together give a palindrome (21311312).

The spelling of 21121311101 in words is "twenty-one billion, one hundred twenty-one million, three hundred eleven thousand, one hundred one".