665970194 has 4 divisors (see below), whose sum is σ = 998955294. Its totient is φ = 332985096.

The previous prime is 665970187. The next prime is 665970203. The reversal of 665970194 is 491079566.

665970194 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 491079566 = 2 ⋅245539783.

It can be written as a sum of positive squares in only one way, i.e., 390576169 + 275394025 = 19763^2 + 16595^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166492547 + ... + 166492550.

Almost surely, 2^665970194 is an apocalyptic number.

665970194 is a deficient number, since it is larger than the sum of its proper divisors (332985100).

665970194 is a wasteful number, since it uses less digits than its factorization.

665970194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332985099.

The product of its (nonzero) digits is 408240, while the sum is 47.

The square root of 665970194 is about 25806.3983151466. The cubic root of 665970194 is about 873.2761462790.

The spelling of 665970194 in words is "six hundred sixty-five million, nine hundred seventy thousand, one hundred ninety-four".