1666201589 has 12 divisors (see below), whose sum is σ = 1816366500. Its totient is φ = 1527686784.

The previous prime is 1666201549. The next prime is 1666201619. The reversal of 1666201589 is 9851026661.

It can be written as a sum of positive squares in 6 ways, for example, as 554979364 + 1111222225 = 23558^2 + 33335^2 .

It is not a de Polignac number, because 1666201589 - 2¹⁶ = 1666136053 is a prime.

It is a super-2 number, since 2×1666201589² = 5552455470372249842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666201529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7904 + ... + 58265.

It is an arithmetic number, because the mean of its divisors is an integer number (151363875).

Almost surely, 2^1666201589 is an apocalyptic number.

It is an amenable number.

1666201589 is a deficient number, since it is larger than the sum of its proper divisors (150164911).

1666201589 is a wasteful number, since it uses less digits than its factorization.

1666201589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66344 (or 66331 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 1666201589 is about 40819.1326340970. The cubic root of 1666201589 is about 1185.5208091279.

The spelling of 1666201589 in words is "one billion, six hundred sixty-six million, two hundred one thousand, five hundred eighty-nine".