78638423 has 2 divisors, whose sum is σ = 78638424. Its totient is φ = 78638422.

The previous prime is 78638387. The next prime is 78638437. The reversal of 78638423 is 32483687.

It is a strong prime.

It is an emirp because it is prime and its reverse (32483687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78638423 - 2¹⁴ = 78622039 is a prime.

It is equal to p_4594577 and since 78638423 and 4594577 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78638453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39319211 + 39319212.

It is an arithmetic number, because the mean of its divisors is an integer number (39319212).

Almost surely, 2^78638423 is an apocalyptic number.

78638423 is a deficient number, since it is larger than the sum of its proper divisors (1).

78638423 is an equidigital number, since it uses as much as digits as its factorization.

78638423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 41.

The square root of 78638423 is about 8867.8307945066. The cubic root of 78638423 is about 428.4284130690.

The spelling of 78638423 in words is "seventy-eight million, six hundred thirty-eight thousand, four hundred twenty-three".