165890846209 has 27 divisors (see below), whose sum is σ = 185686969923. Its totient is φ = 148093189200.

The previous prime is 165890846197. The next prime is 165890846227. The reversal of 165890846209 is 902648098561.

The square root of 165890846209 is 407297.

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., 5394461809 + 160496384400 = 73447^2 + 400620^2 .

It is not a de Polignac number, because 165890846209 - 2³⁷ = 28451892737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165890846269) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 273295984 + ... + 273296590.

Almost surely, 2^165890846209 is an apocalyptic number.

165890846209 is the 407297-th square number.

165890846209 is the 203649-th centered octagonal number.

It is an amenable number.

165890846209 is a deficient number, since it is larger than the sum of its proper divisors (19796123714).

165890846209 is an frugal number, since it uses more digits than its factorization.

165890846209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358 (or 679 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 58.

The spelling of 165890846209 in words is "one hundred sixty-five billion, eight hundred ninety million, eight hundred forty-six thousand, two hundred nine".