78397663 has 4 divisors (see below), whose sum is σ = 78415408. Its totient is φ = 78379920.

The previous prime is 78397651. The next prime is 78397673. The reversal of 78397663 is 36679387.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78397663 - 2²⁵ = 44843231 is a prime.

It is a super-2 number, since 2×78397663² = 12292387127723138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78397633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3595 + ... + 13027.

It is an arithmetic number, because the mean of its divisors is an integer number (19603852).

Almost surely, 2^78397663 is an apocalyptic number.

78397663 is a deficient number, since it is larger than the sum of its proper divisors (17745).

78397663 is an equidigital number, since it uses as much as digits as its factorization.

78397663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17744.

The product of its digits is 1143072, while the sum is 49.

The square root of 78397663 is about 8854.2454788649. The cubic root of 78397663 is about 427.9907395295.

The spelling of 78397663 in words is "seventy-eight million, three hundred ninety-seven thousand, six hundred sixty-three".