12640015 has 4 divisors (see below), whose sum is σ = 15168024. Its totient is φ = 10112008.

The previous prime is 12640009. The next prime is 12640021. The reversal of 12640015 is 51004621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51004621 = 67 ⋅761263.

It is an interprime number because it is at equal distance from previous prime (12640009) and next prime (12640021).

It is a cyclic number.

It is not a de Polignac number, because 12640015 - 2¹¹ = 12637967 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12639974 and 12640001.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1263997 + ... + 1264006.

It is an arithmetic number, because the mean of its divisors is an integer number (3792006).

Almost surely, 2^12640015 is an apocalyptic number.

12640015 is a deficient number, since it is larger than the sum of its proper divisors (2528009).

12640015 is an equidigital number, since it uses as much as digits as its factorization.

12640015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528008.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 12640015 is about 3555.2798764654. The cubic root of 12640015 is about 232.9427490474.

Adding to 12640015 its reverse (51004621), we get a palindrome (63644636).

The spelling of 12640015 in words is "twelve million, six hundred forty thousand, fifteen".