21231120311 has 2 divisors, whose sum is σ = 21231120312. Its totient is φ = 21231120310.

The previous prime is 21231120307. The next prime is 21231120343. The reversal of 21231120311 is 11302113212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231120311 - 2² = 21231120307 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21231120311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231120611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615560155 + 10615560156.

It is an arithmetic number, because the mean of its divisors is an integer number (10615560156).

Almost surely, 2^21231120311 is an apocalyptic number.

21231120311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231120311 is an equidigital number, since it uses as much as digits as its factorization.

21231120311 is an evil number, because the sum of its binary digits is even.

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

Adding to 21231120311 its reverse (11302113212), we get a palindrome (32533233523).

The spelling of 21231120311 in words is "twenty-one billion, two hundred thirty-one million, one hundred twenty thousand, three hundred eleven".