66016889 has 4 divisors (see below), whose sum is σ = 66291060. Its totient is φ = 65742720.

The previous prime is 66016879. The next prime is 66016891. The reversal of 66016889 is 98861066.

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 60295225 + 5721664 = 7765^2 + 2392^2 .

It is a cyclic number.

It is not a de Polignac number, because 66016889 - 2⁸ = 66016633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66016829) 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, 136724 + ... + 137205.

It is an arithmetic number, because the mean of its divisors is an integer number (16572765).

Almost surely, 2^66016889 is an apocalyptic number.

It is an amenable number.

66016889 is a deficient number, since it is larger than the sum of its proper divisors (274171).

66016889 is a wasteful number, since it uses less digits than its factorization.

66016889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274170.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 66016889 is about 8125.0777842431. The cubic root of 66016889 is about 404.1584700833.

The spelling of 66016889 in words is "sixty-six million, sixteen thousand, eight hundred eighty-nine".