78399 has 12 divisors (see below), whose sum is σ = 117312. Its totient is φ = 50400.

The previous prime is 78367. The next prime is 78401. The reversal of 78399 is 99387.

78399 = T₁₆ + T₁₇ + ... + T₇₇.

It is a Cunningham number, because it is equal to 280²-1.

It is not a de Polignac number, because 78399 - 2⁵ = 78367 is a prime.

It is a super-2 number, since 2×78399² = 12292806402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71399) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139 + ... + 419.

It is an arithmetic number, because the mean of its divisors is an integer number (9776).

2⁷⁸³⁹⁹ is an apocalyptic number.

78399 is a deficient number, since it is larger than the sum of its proper divisors (38913).

78399 is a wasteful number, since it uses less digits than its factorization.

78399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 315 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 78399 is about 279.9982142800. The cubic root of 78399 is about 42.7993172512.

The spelling of 78399 in words is "seventy-eight thousand, three hundred ninety-nine".