66078539 has 4 divisors (see below), whose sum is σ = 66195240. Its totient is φ = 65961840.

The previous prime is 66078521. The next prime is 66078557. The reversal of 66078539 is 93587066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93587066 = 2 ⋅46793533.

It is an interprime number because it is at equal distance from previous prime (66078521) and next prime (66078557).

It is a cyclic number.

It is not a de Polignac number, because 66078539 - 2⁸ = 66078283 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66078539.

It is not an unprimeable number, because it can be changed into a prime (66078739) 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, 57497 + ... + 58634.

It is an arithmetic number, because the mean of its divisors is an integer number (16548810).

Almost surely, 2^66078539 is an apocalyptic number.

66078539 is a deficient number, since it is larger than the sum of its proper divisors (116701).

66078539 is a wasteful number, since it uses less digits than its factorization.

66078539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116700.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 66078539 is about 8128.8707087762. The cubic root of 66078539 is about 404.2842389990.

The spelling of 66078539 in words is "sixty-six million, seventy-eight thousand, five hundred thirty-nine".