12640429 has 2 divisors, whose sum is σ = 12640430. Its totient is φ = 12640428.

The previous prime is 12640427. The next prime is 12640451. The reversal of 12640429 is 92404621.

12640429 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9302500 + 3337929 = 3050^2 + 1827^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640429 - 2¹ = 12640427 is a prime.

Together with 12640427, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 12640397 and 12640406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12640427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6320214 + 6320215.

It is an arithmetic number, because the mean of its divisors is an integer number (6320215).

Almost surely, 2^12640429 is an apocalyptic number.

It is an amenable number.

12640429 is a deficient number, since it is larger than the sum of its proper divisors (1).

12640429 is an equidigital number, since it uses as much as digits as its factorization.

12640429 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 12640429 is about 3555.3380992530. The cubic root of 12640429 is about 232.9452922206.

The spelling of 12640429 in words is "twelve million, six hundred forty thousand, four hundred twenty-nine".