166553 has 4 divisors (see below), whose sum is σ = 167808. Its totient is φ = 165300.

The previous prime is 166541. The next prime is 166561. The reversal of 166553 is 355661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 355661 = 19 ⋅18719.

It is a cyclic number.

It is not a de Polignac number, because 166553 - 2⁸ = 166297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401 + ... + 702.

It is an arithmetic number, because the mean of its divisors is an integer number (41952).

2¹⁶⁶⁵⁵³ is an apocalyptic number.

It is an amenable number.

166553 is a deficient number, since it is larger than the sum of its proper divisors (1255).

166553 is a wasteful number, since it uses less digits than its factorization.

166553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254.

The product of its digits is 2700, while the sum is 26.

The square root of 166553 is about 408.1090540530. The cubic root of 166553 is about 55.0196073343.

The spelling of 166553 in words is "one hundred sixty-six thousand, five hundred fifty-three".