665220106 has 4 divisors (see below), whose sum is σ = 997830162. Its totient is φ = 332610052.

The previous prime is 665220097. The next prime is 665220109. The reversal of 665220106 is 601022566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 384356025 + 280864081 = 19605^2 + 16759^2 .

It is not an unprimeable number, because it can be changed into a prime (665220109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166305025 + ... + 166305028.

Almost surely, 2^665220106 is an apocalyptic number.

665220106 is a deficient number, since it is larger than the sum of its proper divisors (332610056).

665220106 is a wasteful number, since it uses less digits than its factorization.

665220106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332610055.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 665220106 is about 25791.8612356689. The cubic root of 665220106 is about 872.9481636148.

The spelling of 665220106 in words is "six hundred sixty-five million, two hundred twenty thousand, one hundred six".