64870639 has 2 divisors, whose sum is σ = 64870640. Its totient is φ = 64870638.

The previous prime is 64870621. The next prime is 64870717. The reversal of 64870639 is 93607846.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64870639 - 2⁵ = 64870607 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64870595 and 64870604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64870339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32435319 + 32435320.

It is an arithmetic number, because the mean of its divisors is an integer number (32435320).

Almost surely, 2^64870639 is an apocalyptic number.

64870639 is a deficient number, since it is larger than the sum of its proper divisors (1).

64870639 is an equidigital number, since it uses as much as digits as its factorization.

64870639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 64870639 is about 8054.2311240739. The cubic root of 64870639 is about 401.8056678935.

The spelling of 64870639 in words is "sixty-four million, eight hundred seventy thousand, six hundred thirty-nine".