665378472706 has 4 divisors (see below), whose sum is σ = 998067709062. Its totient is φ = 332689236352.

The previous prime is 665378472697. The next prime is 665378472713. The reversal of 665378472706 is 607274873566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 607274873566 = 2 ⋅303637436783.

It can be written as a sum of positive squares in only one way, i.e., 462999954481 + 202378518225 = 680441^2 + 449865^2 .

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, 166344618175 + ... + 166344618178.

Almost surely, 2^665378472706 is an apocalyptic number.

665378472706 is a deficient number, since it is larger than the sum of its proper divisors (332689236356).

665378472706 is a wasteful number, since it uses less digits than its factorization.

665378472706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332689236355.

The product of its (nonzero) digits is 71124480, while the sum is 61.

The spelling of 665378472706 in words is "six hundred sixty-five billion, three hundred seventy-eight million, four hundred seventy-two thousand, seven hundred six".