21121320111 has 8 divisors (see below), whose sum is σ = 28420125360. Its totient is φ = 13951697472.

The previous prime is 21121320097. The next prime is 21121320139. The reversal of 21121320111 is 11102312112.

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

It is not a de Polignac number, because 21121320111 - 2⁹ = 21121319599 is a prime.

It is a super-2 number, since 2×21121320111² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121322111) 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, 32295270 + ... + 32295923.

It is an arithmetic number, because the mean of its divisors is an integer number (3552515670).

Almost surely, 2^21121320111 is an apocalyptic number.

21121320111 is a deficient number, since it is larger than the sum of its proper divisors (7298805249).

21121320111 is a wasteful number, since it uses less digits than its factorization.

21121320111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64591305.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21121320111 its reverse (11102312112), we get a palindrome (32223632223).

The spelling of 21121320111 in words is "twenty-one billion, one hundred twenty-one million, three hundred twenty thousand, one hundred eleven".