12312021 has 4 divisors (see below), whose sum is σ = 16416032. Its totient is φ = 8208012.

The previous prime is 12312017. The next prime is 12312023. The reversal of 12312021 is 12021321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 12312021 - 2² = 12312017 is a prime.

It is a super-2 number, since 2×12312021² = 303171722208882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12311988 and 12312006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12312023) 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, 2052001 + ... + 2052006.

It is an arithmetic number, because the mean of its divisors is an integer number (4104008).

Almost surely, 2^12312021 is an apocalyptic number.

It is an amenable number.

12312021 is a deficient number, since it is larger than the sum of its proper divisors (4104011).

12312021 is an equidigital number, since it uses as much as digits as its factorization.

12312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4104010.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 12312021 is about 3508.8489565668. The cubic root of 12312021 is about 230.9101991607.

Adding to 12312021 its reverse (12021321), we get a palindrome (24333342).

The spelling of 12312021 in words is "twelve million, three hundred twelve thousand, twenty-one".