166137209 has 16 divisors (see below), whose sum is σ = 202641408. Its totient is φ = 132959232.

The previous prime is 166137203. The next prime is 166137217. The reversal of 166137209 is 902731661.

It is not a de Polignac number, because 166137209 - 2¹⁶ = 166071673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166137203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9617 + ... + 20609.

It is an arithmetic number, because the mean of its divisors is an integer number (12665088).

Almost surely, 2^166137209 is an apocalyptic number.

It is an amenable number.

166137209 is a deficient number, since it is larger than the sum of its proper divisors (36504199).

166137209 is a wasteful number, since it uses less digits than its factorization.

166137209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11144.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 166137209 is about 12889.4223687487. The cubic root of 166137209 is about 549.7378464161.

The spelling of 166137209 in words is "one hundred sixty-six million, one hundred thirty-seven thousand, two hundred nine".