12640013 has 4 divisors (see below), whose sum is σ = 12948348. Its totient is φ = 12331680.

The previous prime is 12640009. The next prime is 12640021. The reversal of 12640013 is 31004621.

12640013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31004621 = 23 ⋅1348027.

It can be written as a sum of positive squares in 2 ways, for example, as 228484 + 12411529 = 478^2 + 3523^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640013 - 2² = 12640009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12639973 and 12640000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640003) 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, 154106 + ... + 154187.

It is an arithmetic number, because the mean of its divisors is an integer number (3237087).

Almost surely, 2^12640013 is an apocalyptic number.

It is an amenable number.

12640013 is a deficient number, since it is larger than the sum of its proper divisors (308335).

12640013 is an equidigital number, since it uses as much as digits as its factorization.

12640013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308334.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 12640013 is about 3555.2795951936. The cubic root of 12640013 is about 232.9427367614.

Adding to 12640013 its reverse (31004621), we get a palindrome (43644634).

The spelling of 12640013 in words is "twelve million, six hundred forty thousand, thirteen".