21211020311 has 4 divisors (see below), whose sum is σ = 22842637272. Its totient is φ = 19579403352.

The previous prime is 21211020269. The next prime is 21211020323. The reversal of 21211020311 is 11302011212.

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 21211020311 - 2²⁶ = 21143911447 is a prime.

It is a super-3 number, since 3×21211020311³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211022311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815808461 + ... + 815808486.

It is an arithmetic number, because the mean of its divisors is an integer number (5710659318).

Almost surely, 2^21211020311 is an apocalyptic number.

21211020311 is a deficient number, since it is larger than the sum of its proper divisors (1631616961).

21211020311 is a wasteful number, since it uses less digits than its factorization.

21211020311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631616960.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21211020311 its reverse (11302011212), we get a palindrome (32513031523).

Subtracting from 21211020311 its reverse (11302011212), we obtain a palindrome (9909009099).

The spelling of 21211020311 in words is "twenty-one billion, two hundred eleven million, twenty thousand, three hundred eleven".