166375553 has 4 divisors (see below), whose sum is σ = 166452948. Its totient is φ = 166298160.

The previous prime is 166375511. The next prime is 166375579. The reversal of 166375553 is 355573661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 355573661 = 53 ⋅6708937.

It can be written as a sum of positive squares in 2 ways, for example, as 143832049 + 22543504 = 11993^2 + 4748^2 .

It is a cyclic number.

It is not a de Polignac number, because 166375553 - 2¹⁴ = 166359169 is a prime.

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 166375553.

It is not an unprimeable number, because it can be changed into a prime (166375453) 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, 35378 + ... + 39803.

It is an arithmetic number, because the mean of its divisors is an integer number (41613237).

Almost surely, 2^166375553 is an apocalyptic number.

It is an amenable number.

166375553 is a deficient number, since it is larger than the sum of its proper divisors (77395).

166375553 is an equidigital number, since it uses as much as digits as its factorization.

166375553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77394.

The product of its digits is 283500, while the sum is 41.

The square root of 166375553 is about 12898.6647758596. The cubic root of 166375553 is about 550.0006093657. Note that the first 3 decimals are identical.

The spelling of 166375553 in words is "one hundred sixty-six million, three hundred seventy-five thousand, five hundred fifty-three".