166335912649 has 3 divisors (see below), whose sum is σ = 166336320493. Its totient is φ = 166335504806.

The previous prime is 166335912641. The next prime is 166335912719. The reversal of 166335912649 is 946219533661.

The square root of 166335912649 is 407843.

It is a perfect power (a square), and thus also a powerful number.

166335912649 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 is not a de Polignac number, because 166335912649 - 2³ = 166335912641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166335912649.

It is not an unprimeable number, because it can be changed into a prime (166335912641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 203922 + ... + 611764.

Almost surely, 2^166335912649 is an apocalyptic number.

166335912649 is the 407843-rd square number.

166335912649 is the 203922-nd centered octagonal number.

It is an amenable number.

166335912649 is a deficient number, since it is larger than the sum of its proper divisors (407844).

166335912649 is an frugal number, since it uses more digits than its factorization.

166335912649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 815686 (or 407843 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 55.

The spelling of 166335912649 in words is "one hundred sixty-six billion, three hundred thirty-five million, nine hundred twelve thousand, six hundred forty-nine".