66043885 has 4 divisors (see below), whose sum is σ = 79252668. Its totient is φ = 52835104.

The previous prime is 66043877. The next prime is 66043891. The reversal of 66043885 is 58834066.

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 45414121 + 20629764 = 6739^2 + 4542^2 .

It is a cyclic number.

It is not a de Polignac number, because 66043885 - 2³ = 66043877 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian 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, 6604384 + ... + 6604393.

It is an arithmetic number, because the mean of its divisors is an integer number (19813167).

Almost surely, 2^66043885 is an apocalyptic number.

It is an amenable number.

66043885 is a deficient number, since it is larger than the sum of its proper divisors (13208783).

66043885 is a wasteful number, since it uses less digits than its factorization.

66043885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13208782.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 66043885 is about 8126.7388908467. The cubic root of 66043885 is about 404.2135528323.

The spelling of 66043885 in words is "sixty-six million, forty-three thousand, eight hundred eighty-five".