166261505 has 8 divisors (see below), whose sum is σ = 202492032. Its totient is φ = 131023728.

The previous prime is 166261493. The next prime is 166261507. The reversal of 166261505 is 505162661.

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

It is a cyclic number.

It is not a de Polignac number, because 166261505 - 2¹⁰ = 166260481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166261507) 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 7 ways as a sum of consecutive naturals, for example, 247817 + ... + 248486.

It is an arithmetic number, because the mean of its divisors is an integer number (25311504).

Almost surely, 2^166261505 is an apocalyptic number.

It is an amenable number.

166261505 is a deficient number, since it is larger than the sum of its proper divisors (36230527).

166261505 is an equidigital number, since it uses as much as digits as its factorization.

166261505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496375.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 166261505 is about 12894.2430952732. The cubic root of 166261505 is about 549.8749081904.

The spelling of 166261505 in words is "one hundred sixty-six million, two hundred sixty-one thousand, five hundred five".