166910651209 has 9 divisors (see below), whose sum is σ = 167835364263. Its totient is φ = 165991011912.

The previous prime is 166910651203. The next prime is 166910651231. The reversal of 166910651209 is 902156019661.

It is a happy number.

The square root of 166910651209 is 408547.

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

It can be written as a sum of positive squares in only one way, i.e., 86156925625 + 80753725584 = 293525^2 + 284172^2 .

It is not a de Polignac number, because 166910651209 - 2²⁹ = 166373780297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166910651203) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 81299827 + ... + 81301879.

It is an arithmetic number, because the mean of its divisors is an integer number (18648373807).

Almost surely, 2^166910651209 is an apocalyptic number.

166910651209 is the 408547-th square number.

166910651209 is the 204274-th centered octagonal number.

It is an amenable number.

166910651209 is a deficient number, since it is larger than the sum of its proper divisors (924713054).

166910651209 is an frugal number, since it uses more digits than its factorization.

166910651209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504 (or 2252 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 46.

The spelling of 166910651209 in words is "one hundred sixty-six billion, nine hundred ten million, six hundred fifty-one thousand, two hundred nine".