21023311311 has 24 divisors (see below), whose sum is σ = 32829204720. Its totient is φ = 12919015296.

The previous prime is 21023311291. The next prime is 21023311313. The reversal of 21023311311 is 11311332012.

21023311311 is a `hidden beast` number, since 21 + 0 + 2 + 331 + 1 + 311 = 666.

It is not a de Polignac number, because 21023311311 - 2⁶ = 21023311247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023311313) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1655070 + ... + 1667723.

It is an arithmetic number, because the mean of its divisors is an integer number (1367883530).

Almost surely, 2^21023311311 is an apocalyptic number.

21023311311 is a deficient number, since it is larger than the sum of its proper divisors (11805893409).

21023311311 is a wasteful number, since it uses less digits than its factorization.

21023311311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3322855 (or 3322852 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21023311311 its reverse (11311332012), we get a palindrome (32334643323).

The spelling of 21023311311 in words is "twenty-one billion, twenty-three million, three hundred eleven thousand, three hundred eleven".