78578559 has 16 divisors (see below), whose sum is σ = 116838240. Its totient is φ = 52194240.

The previous prime is 78578543. The next prime is 78578561. The reversal of 78578559 is 95587587.

78578559 is a `hidden beast` number, since 7 + 85 + 7 + 8 + 559 = 666.

It is not a de Polignac number, because 78578559 - 2⁴ = 78578543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78578569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2409 + ... + 12765.

It is an arithmetic number, because the mean of its divisors is an integer number (7302390).

Almost surely, 2^78578559 is an apocalyptic number.

78578559 is a deficient number, since it is larger than the sum of its proper divisors (38259681).

78578559 is a wasteful number, since it uses less digits than its factorization.

78578559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10647 (or 10641 counting only the distinct ones).

The product of its digits is 3528000, while the sum is 54.

The square root of 78578559 is about 8864.4548055704. The cubic root of 78578559 is about 428.3196708520.

Subtracting 78578559 from its reverse (95587587), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 78578559 in words is "seventy-eight million, five hundred seventy-eight thousand, five hundred fifty-nine".