64638439 has 2 divisors, whose sum is σ = 64638440. Its totient is φ = 64638438.

The previous prime is 64638433. The next prime is 64638449. The reversal of 64638439 is 93483646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64638439 - 2⁷ = 64638311 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64638395 and 64638404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64638433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32319219 + 32319220.

It is an arithmetic number, because the mean of its divisors is an integer number (32319220).

Almost surely, 2^64638439 is an apocalyptic number.

64638439 is a deficient number, since it is larger than the sum of its proper divisors (1).

64638439 is an equidigital number, since it uses as much as digits as its factorization.

64638439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 43.

The square root of 64638439 is about 8039.8034179947. The cubic root of 64638439 is about 401.3256828090.

The spelling of 64638439 in words is "sixty-four million, six hundred thirty-eight thousand, four hundred thirty-nine".