166553801 has 4 divisors (see below), whose sum is σ = 166874004. Its totient is φ = 166233600.

The previous prime is 166553797. The next prime is 166553809. The reversal of 166553801 is 108355661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 108355661 = 41 ⋅2642821.

It can be written as a sum of positive squares in 2 ways, for example, as 16613776 + 149940025 = 4076^2 + 12245^2 .

It is a cyclic number.

It is not a de Polignac number, because 166553801 - 2² = 166553797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166553809) 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, 159320 + ... + 160361.

It is an arithmetic number, because the mean of its divisors is an integer number (41718501).

Almost surely, 2^166553801 is an apocalyptic number.

It is an amenable number.

166553801 is a deficient number, since it is larger than the sum of its proper divisors (320203).

166553801 is an equidigital number, since it uses as much as digits as its factorization.

166553801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320202.

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 166553801 is about 12905.5724785846. The cubic root of 166553801 is about 550.1969553571.

The spelling of 166553801 in words is "one hundred sixty-six million, five hundred fifty-three thousand, eight hundred one".