21121311311 has 8 divisors (see below), whose sum is σ = 21254872320. Its totient is φ = 20987799192.

The previous prime is 21121311307. The next prime is 21121311359. The reversal of 21121311311 is 11311312112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21121311311 - 2² = 21121311307 is a prime.

It is a super-2 number, since 2×21121311311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121311311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121311371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1282616 + ... + 1298978.

It is an arithmetic number, because the mean of its divisors is an integer number (2656859040).

Almost surely, 2^21121311311 is an apocalyptic number.

21121311311 is a deficient number, since it is larger than the sum of its proper divisors (133561009).

21121311311 is a wasteful number, since it uses less digits than its factorization.

21121311311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24445.

The product of its digits is 36, while the sum is 17.

Adding to 21121311311 its reverse (11311312112), we get a palindrome (32432623423).

The spelling of 21121311311 in words is "twenty-one billion, one hundred twenty-one million, three hundred eleven thousand, three hundred eleven".