12640257 has 12 divisors (see below), whose sum is σ = 20866560. Its totient is φ = 7222968.

The previous prime is 12640247. The next prime is 12640261. The reversal of 12640257 is 75204621.

12640257 is a `hidden beast` number, since 12 + 640 + 2 + 5 + 7 = 666.

12640257 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12640257 - 2⁴ = 12640241 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12640257.

It is not an unprimeable number, because it can be changed into a prime (12640207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 100257 + ... + 100382.

It is an arithmetic number, because the mean of its divisors is an integer number (1738880).

It is a Proth number, since it is equal to 1543 ⋅ 2¹³ + 1 and 1543 < 2¹³.

Almost surely, 2^12640257 is an apocalyptic number.

It is an amenable number.

12640257 is a deficient number, since it is larger than the sum of its proper divisors (8226303).

12640257 is a wasteful number, since it uses less digits than its factorization.

12640257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200652 (or 200649 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 12640257 is about 3555.3139101913. The cubic root of 12640257 is about 232.9442356433.

Adding to 12640257 its reverse (75204621), we get a palindrome (87844878).

The spelling of 12640257 in words is "twelve million, six hundred forty thousand, two hundred fifty-seven".