21120321311 has 4 divisors (see below), whose sum is σ = 21188232624. Its totient is φ = 21052410000.

The previous prime is 21120321307. The next prime is 21120321319. The reversal of 21120321311 is 11312302112.

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 21120321311 - 2² = 21120321307 is a prime.

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 21120321311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120321319) 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, 33955190 + ... + 33955811.

It is an arithmetic number, because the mean of its divisors is an integer number (5297058156).

Almost surely, 2^21120321311 is an apocalyptic number.

21120321311 is a deficient number, since it is larger than the sum of its proper divisors (67911313).

21120321311 is an equidigital number, since it uses as much as digits as its factorization.

21120321311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67911312.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21120321311 its reverse (11312302112), we get a palindrome (32432623423).

The spelling of 21120321311 in words is "twenty-one billion, one hundred twenty million, three hundred twenty-one thousand, three hundred eleven".