66078605 has 4 divisors (see below), whose sum is σ = 79294332. Its totient is φ = 52862880.

The previous prime is 66078557. The next prime is 66078629. The reversal of 66078605 is 50687066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 46267204 + 19811401 = 6802^2 + 4451^2 .

It is not a de Polignac number, because 66078605 - 2²⁰ = 65030029 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6607856 + ... + 6607865.

It is an arithmetic number, because the mean of its divisors is an integer number (19823583).

Almost surely, 2^66078605 is an apocalyptic number.

It is an amenable number.

66078605 is a deficient number, since it is larger than the sum of its proper divisors (13215727).

66078605 is a wasteful number, since it uses less digits than its factorization.

66078605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13215726.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 66078605 is about 8128.8747683797. The cubic root of 66078605 is about 404.2843736002.

The spelling of 66078605 in words is "sixty-six million, seventy-eight thousand, six hundred five".