21312203311 has 4 divisors (see below), whose sum is σ = 24356803792. Its totient is φ = 18267602832.

The previous prime is 21312203303. The next prime is 21312203321. The reversal of 21312203311 is 11330221312.

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 21312203311 - 2³ = 21312203303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312203321) 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, 1522300230 + ... + 1522300243.

It is an arithmetic number, because the mean of its divisors is an integer number (6089200948).

Almost surely, 2^21312203311 is an apocalyptic number.

21312203311 is a deficient number, since it is larger than the sum of its proper divisors (3044600481).

21312203311 is an equidigital number, since it uses as much as digits as its factorization.

21312203311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3044600480.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21312203311 its reverse (11330221312), we get a palindrome (32642424623).

The spelling of 21312203311 in words is "twenty-one billion, three hundred twelve million, two hundred three thousand, three hundred eleven".