1966806559 has 4 divisors (see below), whose sum is σ = 1979831920. Its totient is φ = 1953781200.

The previous prime is 1966806557. The next prime is 1966806587. The reversal of 1966806559 is 9556086691.

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

It is a cyclic number.

It is not a de Polignac number, because 1966806559 - 2¹ = 1966806557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1966806557) 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, 6512454 + ... + 6512755.

It is an arithmetic number, because the mean of its divisors is an integer number (494957980).

Almost surely, 2^1966806559 is an apocalyptic number.

1966806559 is a deficient number, since it is larger than the sum of its proper divisors (13025361).

1966806559 is a wasteful number, since it uses less digits than its factorization.

1966806559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13025360.

The product of its (nonzero) digits is 3499200, while the sum is 55.

The square root of 1966806559 is about 44348.6928668704. The cubic root of 1966806559 is about 1252.9119437858.

The spelling of 1966806559 in words is "one billion, nine hundred sixty-six million, eight hundred six thousand, five hundred fifty-nine".