166203649 has 4 divisors (see below), whose sum is σ = 169020720. Its totient is φ = 163386580.

The previous prime is 166203641. The next prime is 166203671. The reversal of 166203649 is 946302661.

It is a happy number.

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: 946302661 = 167 ⋅5666483.

It is a cyclic number.

It is not a de Polignac number, because 166203649 - 2³ = 166203641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166203641) 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, 1408447 + ... + 1408564.

It is an arithmetic number, because the mean of its divisors is an integer number (42255180).

Almost surely, 2^166203649 is an apocalyptic number.

It is an amenable number.

166203649 is a deficient number, since it is larger than the sum of its proper divisors (2817071).

166203649 is an equidigital number, since it uses as much as digits as its factorization.

166203649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2817070.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 166203649 is about 12891.9994182439. Note that the first 3 decimals coincide. The cubic root of 166203649 is about 549.8111186127.

The spelling of 166203649 in words is "one hundred sixty-six million, two hundred three thousand, six hundred forty-nine".