201661239 has 16 divisors (see below), whose sum is σ = 290525312. Its totient is φ = 123687648.

The previous prime is 201661177. The next prime is 201661241. The reversal of 201661239 is 932166102.

It is not a de Polignac number, because 201661239 - 2⁹ = 201660727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201661279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3552 + ... + 20394.

It is an arithmetic number, because the mean of its divisors is an integer number (18157832).

Almost surely, 2^201661239 is an apocalyptic number.

201661239 is a deficient number, since it is larger than the sum of its proper divisors (88864073).

201661239 is a wasteful number, since it uses less digits than its factorization.

201661239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17166.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 201661239 is about 14200.7478324207. The cubic root of 201661239 is about 586.4182492861.

The spelling of 201661239 in words is "two hundred one million, six hundred sixty-one thousand, two hundred thirty-nine".