12640055 has 4 divisors (see below), whose sum is σ = 15168072. Its totient is φ = 10112040.

The previous prime is 12640037. The next prime is 12640091. The reversal of 12640055 is 55004621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55004621 = 7 ⋅7857803.

It is not a de Polignac number, because 12640055 - 2¹⁰ = 12639031 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12640055.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1264001 + ... + 1264010.

It is an arithmetic number, because the mean of its divisors is an integer number (3792018).

Almost surely, 2^12640055 is an apocalyptic number.

12640055 is a deficient number, since it is larger than the sum of its proper divisors (2528017).

12640055 is an equidigital number, since it uses as much as digits as its factorization.

12640055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2528016.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 12640055 is about 3555.2855018971. The cubic root of 12640055 is about 232.9429947670.

Adding to 12640055 its reverse (55004621), we get a palindrome (67644676).

The spelling of 12640055 in words is "twelve million, six hundred forty thousand, fifty-five".