78399427 has 4 divisors (see below), whose sum is σ = 83011176. Its totient is φ = 73787680.

The previous prime is 78399401. The next prime is 78399437. The reversal of 78399427 is 72499387.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72499387 = 311 ⋅233117.

It is a cyclic number.

It is not a de Polignac number, because 78399427 - 2¹¹ = 78397379 is a prime.

It is a super-2 number, since 2×78399427² = 12292940307856658, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78399437) 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, 2305849 + ... + 2305882.

It is an arithmetic number, because the mean of its divisors is an integer number (20752794).

Almost surely, 2^78399427 is an apocalyptic number.

78399427 is a deficient number, since it is larger than the sum of its proper divisors (4611749).

78399427 is a wasteful number, since it uses less digits than its factorization.

78399427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4611748.

The product of its digits is 762048, while the sum is 49.

The square root of 78399427 is about 8854.3450915356. The cubic root of 78399427 is about 427.9939495316.

The spelling of 78399427 in words is "seventy-eight million, three hundred ninety-nine thousand, four hundred twenty-seven".