12021020311 has 4 divisors (see below), whose sum is σ = 12543673392. Its totient is φ = 11498367232.

The previous prime is 12021020309. The next prime is 12021020329. The reversal of 12021020311 is 11302012021.

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 12021020311 - 2¹ = 12021020309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12021020291 and 12021020300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12021020351) 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, 261326506 + ... + 261326551.

It is an arithmetic number, because the mean of its divisors is an integer number (3135918348).

Almost surely, 2^12021020311 is an apocalyptic number.

12021020311 is a deficient number, since it is larger than the sum of its proper divisors (522653081).

12021020311 is an equidigital number, since it uses as much as digits as its factorization.

12021020311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522653080.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 12021020311 its reverse (11302012021), we get a palindrome (23323032332).

The spelling of 12021020311 in words is "twelve billion, twenty-one million, twenty thousand, three hundred eleven".