78878539 has 4 divisors (see below), whose sum is σ = 81423040. Its totient is φ = 76334040.

The previous prime is 78878509. The next prime is 78878599. The reversal of 78878539 is 93587887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93587887 = 1783 ⋅52489.

It is a cyclic number.

It is not a de Polignac number, because 78878539 - 2⁹ = 78878027 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 78878539.

It is not an unprimeable number, because it can be changed into a prime (78878509) 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, 1272204 + ... + 1272265.

It is an arithmetic number, because the mean of its divisors is an integer number (20355760).

Almost surely, 2^78878539 is an apocalyptic number.

78878539 is a deficient number, since it is larger than the sum of its proper divisors (2544501).

78878539 is a wasteful number, since it uses less digits than its factorization.

78878539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2544500.

The product of its digits is 3386880, while the sum is 55.

The square root of 78878539 is about 8881.3590739256. The cubic root of 78878539 is about 428.8640270513.

The spelling of 78878539 in words is "seventy-eight million, eight hundred seventy-eight thousand, five hundred thirty-nine".