166531261 has 8 divisors (see below), whose sum is σ = 180712224. Its totient is φ = 152546160.

The previous prime is 166531237. The next prime is 166531273. The reversal of 166531261 is 162135661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166531261 - 2¹³ = 166523069 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 (166538261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47191 + ... + 50596.

It is an arithmetic number, because the mean of its divisors is an integer number (22589028).

Almost surely, 2^166531261 is an apocalyptic number.

It is an amenable number.

166531261 is a deficient number, since it is larger than the sum of its proper divisors (14180963).

166531261 is a wasteful number, since it uses less digits than its factorization.

166531261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97931.

The product of its digits is 6480, while the sum is 31.

The square root of 166531261 is about 12904.6991828558. The cubic root of 166531261 is about 550.1721345509.

The spelling of 166531261 in words is "one hundred sixty-six million, five hundred thirty-one thousand, two hundred sixty-one".