166561135 has 16 divisors (see below), whose sum is σ = 216953856. Its totient is φ = 122024448.

The previous prime is 166561133. The next prime is 166561141. The reversal of 166561135 is 531165661.

It is not a de Polignac number, because 166561135 - 2¹ = 166561133 is a prime.

It is a super-2 number, since 2×166561135² = 55485223384976450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166561135.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166561133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1834 + ... + 18343.

It is an arithmetic number, because the mean of its divisors is an integer number (13559616).

Almost surely, 2^166561135 is an apocalyptic number.

166561135 is a deficient number, since it is larger than the sum of its proper divisors (50392721).

166561135 is a wasteful number, since it uses less digits than its factorization.

166561135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20322.

The product of its digits is 16200, while the sum is 34.

The square root of 166561135 is about 12905.8566162808. The cubic root of 166561135 is about 550.2050309963.

The spelling of 166561135 in words is "one hundred sixty-six million, five hundred sixty-one thousand, one hundred thirty-five".