166521233 has 4 divisors (see below), whose sum is σ = 168138048. Its totient is φ = 164904420.

The previous prime is 166521221. The next prime is 166521247. The reversal of 166521233 is 332125661.

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.

It is a cyclic number.

It is not a de Polignac number, because 166521233 - 2⁴ = 166521217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166521196 and 166521205.

It is not an unprimeable number, because it can be changed into a prime (166521293) 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, 808253 + ... + 808458.

It is an arithmetic number, because the mean of its divisors is an integer number (42034512).

Almost surely, 2^166521233 is an apocalyptic number.

It is an amenable number.

166521233 is a deficient number, since it is larger than the sum of its proper divisors (1616815).

166521233 is a wasteful number, since it uses less digits than its factorization.

166521233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1616814.

The product of its digits is 6480, while the sum is 29.

The square root of 166521233 is about 12904.3106363726. The cubic root of 166521233 is about 550.1610911050.

Adding to 166521233 its reverse (332125661), we get a palindrome (498646894).

The spelling of 166521233 in words is "one hundred sixty-six million, five hundred twenty-one thousand, two hundred thirty-three".