12640471 has 4 divisors (see below), whose sum is σ = 12693600. Its totient is φ = 12587344.

The previous prime is 12640451. The next prime is 12640477. The reversal of 12640471 is 17404621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12640471 is a prime.

It is a super-3 number, since 3×12640471³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26206 + ... + 26683.

It is an arithmetic number, because the mean of its divisors is an integer number (3173400).

Almost surely, 2^12640471 is an apocalyptic number.

12640471 is a deficient number, since it is larger than the sum of its proper divisors (53129).

12640471 is an equidigital number, since it uses as much as digits as its factorization.

12640471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53128.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 12640471 is about 3555.3440058593. The cubic root of 12640471 is about 232.9455502206.

The spelling of 12640471 in words is "twelve million, six hundred forty thousand, four hundred seventy-one".