12431021 has 4 divisors (see below), whose sum is σ = 12482844. Its totient is φ = 12379200.

The previous prime is 12430963. The next prime is 12431033. The reversal of 12431021 is 12013421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12013421 = 7 ⋅1716203.

It can be written as a sum of positive squares in 2 ways, for example, as 3496900 + 8934121 = 1870^2 + 2989^2 .

It is a cyclic number.

It is not a de Polignac number, because 12431021 - 2²² = 8236717 is a prime.

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 = 12430987 and 12431005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12431071) 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, 25550 + ... + 26031.

It is an arithmetic number, because the mean of its divisors is an integer number (3120711).

Almost surely, 2^12431021 is an apocalyptic number.

It is an amenable number.

12431021 is a deficient number, since it is larger than the sum of its proper divisors (51823).

12431021 is an equidigital number, since it uses as much as digits as its factorization.

12431021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51822.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 12431021 is about 3525.7653069936. The cubic root of 12431021 is about 231.6517578062.

Adding to 12431021 its reverse (12013421), we get a palindrome (24444442).

The spelling of 12431021 in words is "twelve million, four hundred thirty-one thousand, twenty-one".