166620154 has 4 divisors (see below), whose sum is σ = 249930234. Its totient is φ = 83310076.

The previous prime is 166620137. The next prime is 166620161. The reversal of 166620154 is 451026661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 451026661 = 53 ⋅8509937.

It can be written as a sum of positive squares in only one way, i.e., 149206225 + 17413929 = 12215^2 + 4173^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41655037 + ... + 41655040.

Almost surely, 2^166620154 is an apocalyptic number.

166620154 is a deficient number, since it is larger than the sum of its proper divisors (83310080).

166620154 is an equidigital number, since it uses as much as digits as its factorization.

166620154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83310079.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 166620154 is about 12908.1429338228. The cubic root of 166620154 is about 550.2700095722.

The spelling of 166620154 in words is "one hundred sixty-six million, six hundred twenty thousand, one hundred fifty-four".