78638387 has 2 divisors, whose sum is σ = 78638388. Its totient is φ = 78638386.

The previous prime is 78638381. The next prime is 78638423. The reversal of 78638387 is 78383687.

It is a weak prime.

It is an emirp because it is prime and its reverse (78383687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78638387 - 2¹² = 78634291 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78638381) 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, 39319193 + 39319194.

It is an arithmetic number, because the mean of its divisors is an integer number (39319194).

Almost surely, 2^78638387 is an apocalyptic number.

78638387 is a deficient number, since it is larger than the sum of its proper divisors (1).

78638387 is an equidigital number, since it uses as much as digits as its factorization.

78638387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 50.

The square root of 78638387 is about 8867.8287646977. The cubic root of 78638387 is about 428.4283476920.

The spelling of 78638387 in words is "seventy-eight million, six hundred thirty-eight thousand, three hundred eighty-seven".