16648666 has 4 divisors (see below), whose sum is σ = 24973002. Its totient is φ = 8324332.

The previous prime is 16648663. The next prime is 16648673. The reversal of 16648666 is 66684661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66684661 = 19 ⋅3509719.

It can be written as a sum of positive squares in only one way, i.e., 16573041 + 75625 = 4071^2 + 275^2 .

It is not an unprimeable number, because it can be changed into a prime (16648663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4162165 + ... + 4162168.

Almost surely, 2^16648666 is an apocalyptic number.

16648666 is a deficient number, since it is larger than the sum of its proper divisors (8324336).

16648666 is an equidigital number, since it uses as much as digits as its factorization.

16648666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8324335.

The product of its digits is 248832, while the sum is 43.

The square root of 16648666 is about 4080.2776866287. The cubic root of 16648666 is about 255.3444837999.

The spelling of 16648666 in words is "sixteen million, six hundred forty-eight thousand, six hundred sixty-six".