166624553 has 4 divisors (see below), whose sum is σ = 166688340. Its totient is φ = 166560768.

The previous prime is 166624543. The next prime is 166624559. The reversal of 166624553 is 355426661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 355426661 = 311 ⋅1142851.

It can be written as a sum of positive squares in 2 ways, for example, as 156075049 + 10549504 = 12493^2 + 3248^2 .

It is a cyclic number.

It is not a de Polignac number, because 166624553 - 2⁴ = 166624537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166624559) 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 3 ways as a sum of consecutive naturals, for example, 27800 + ... + 33257.

It is an arithmetic number, because the mean of its divisors is an integer number (41672085).

Almost surely, 2^166624553 is an apocalyptic number.

It is an amenable number.

166624553 is a deficient number, since it is larger than the sum of its proper divisors (63787).

166624553 is an equidigital number, since it uses as much as digits as its factorization.

166624553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63786.

The product of its digits is 129600, while the sum is 38.

The square root of 166624553 is about 12908.3133290140. The cubic root of 166624553 is about 550.2748521566.

The spelling of 166624553 in words is "one hundred sixty-six million, six hundred twenty-four thousand, five hundred fifty-three".