78397 has 4 divisors (see below), whose sum is σ = 85536. Its totient is φ = 71260.

The previous prime is 78367. The next prime is 78401. The reversal of 78397 is 79387.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78397 is a prime.

It is a super-2 number, since 2×78397² = 12292179218, which contains 22 as substring.

78397 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3553 + ... + 3574.

It is an arithmetic number, because the mean of its divisors is an integer number (21384).

2⁷⁸³⁹⁷ is an apocalyptic number.

It is an amenable number.

78397 is a deficient number, since it is larger than the sum of its proper divisors (7139).

78397 is a wasteful number, since it uses less digits than its factorization.

78397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7138.

The product of its digits is 10584, while the sum is 34.

The square root of 78397 is about 279.9946428059. The cubic root of 78397 is about 42.7989533037.

Subtracting 78397 from its reverse (79387), we obtain a triangular number (990 = T₄₄).

The spelling of 78397 in words is "seventy-eight thousand, three hundred ninety-seven".