78378623 has 2 divisors, whose sum is σ = 78378624. Its totient is φ = 78378622.

The previous prime is 78378613. The next prime is 78378647. The reversal of 78378623 is 32687387.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78378623 - 2⁴ = 78378607 is a prime.

It is a super-2 number, since 2×78378623² = 12286417086752258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78378613) 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, 39189311 + 39189312.

It is an arithmetic number, because the mean of its divisors is an integer number (39189312).

Almost surely, 2^78378623 is an apocalyptic number.

78378623 is a deficient number, since it is larger than the sum of its proper divisors (1).

78378623 is an equidigital number, since it uses as much as digits as its factorization.

78378623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 44.

The square root of 78378623 is about 8853.1702231461. The cubic root of 78378623 is about 427.9560888220.

The spelling of 78378623 in words is "seventy-eight million, three hundred seventy-eight thousand, six hundred twenty-three".