20111221311 has 4 divisors (see below), whose sum is σ = 26814961752. Its totient is φ = 13407480872.

The previous prime is 20111221301. The next prime is 20111221337. The reversal of 20111221311 is 11312211102.

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 20111221311 - 2⁵ = 20111221279 is a prime.

It is a super-2 number, since 2×20111221311² (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 (20111221301) 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, 3351870216 + ... + 3351870221.

It is an arithmetic number, because the mean of its divisors is an integer number (6703740438).

Almost surely, 2^20111221311 is an apocalyptic number.

20111221311 is a deficient number, since it is larger than the sum of its proper divisors (6703740441).

20111221311 is an equidigital number, since it uses as much as digits as its factorization.

20111221311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6703740440.

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

Adding to 20111221311 its reverse (11312211102), we get a palindrome (31423432413).

The spelling of 20111221311 in words is "twenty billion, one hundred eleven million, two hundred twenty-one thousand, three hundred eleven".