166513281 has 16 divisors (see below), whose sum is σ = 246309120. Its totient is φ = 99205520.

The previous prime is 166513279. The next prime is 166513289. The reversal of 166513281 is 182315661.

It is a cyclic number.

It is not a de Polignac number, because 166513281 - 2¹ = 166513279 is a prime.

It is a super-2 number, since 2×166513281² = 55453345498769922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166513289) 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, 40815 + ... + 44708.

It is an arithmetic number, because the mean of its divisors is an integer number (15394320).

Almost surely, 2^166513281 is an apocalyptic number.

166513281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166513281 is a deficient number, since it is larger than the sum of its proper divisors (79795839).

166513281 is a wasteful number, since it uses less digits than its factorization.

166513281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85596.

The product of its digits is 8640, while the sum is 33.

The square root of 166513281 is about 12904.0025185986. The cubic root of 166513281 is about 550.1523335618.

The spelling of 166513281 in words is "one hundred sixty-six million, five hundred thirteen thousand, two hundred eighty-one".