12640137 has 4 divisors (see below), whose sum is σ = 16853520. Its totient is φ = 8426756.

The previous prime is 12640123. The next prime is 12640141. The reversal of 12640137 is 73104621.

12640137 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12640137 - 2⁷ = 12640009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12640037) 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, 2106687 + ... + 2106692.

It is an arithmetic number, because the mean of its divisors is an integer number (4213380).

Almost surely, 2^12640137 is an apocalyptic number.

It is an amenable number.

12640137 is a deficient number, since it is larger than the sum of its proper divisors (4213383).

12640137 is an equidigital number, since it uses as much as digits as its factorization.

12640137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4213382.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 12640137 is about 3555.2970340043. The cubic root of 12640137 is about 232.9434984907.

Adding to 12640137 its reverse (73104621), we get a palindrome (85744758).

The spelling of 12640137 in words is "twelve million, six hundred forty thousand, one hundred thirty-seven".