66166401089 has 4 divisors (see below), whose sum is σ = 66167037060. Its totient is φ = 66165765120.

The previous prime is 66166401079. The next prime is 66166401109. The reversal of 66166401089 is 98010466166.

66166401089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 23355480625 + 42810920464 = 152825^2 + 206908^2 .

It is a cyclic number.

It is not a de Polignac number, because 66166401089 - 2¹⁶ = 66166335553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66166401079) 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, 121424 + ... + 383505.

It is an arithmetic number, because the mean of its divisors is an integer number (16541759265).

Almost surely, 2^66166401089 is an apocalyptic number.

It is an amenable number.

66166401089 is a deficient number, since it is larger than the sum of its proper divisors (635971).

66166401089 is a wasteful number, since it uses less digits than its factorization.

66166401089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635970.

The product of its (nonzero) digits is 373248, while the sum is 47.

The spelling of 66166401089 in words is "sixty-six billion, one hundred sixty-six million, four hundred one thousand, eighty-nine".