668017442 has 4 divisors (see below), whose sum is σ = 1002026166. Its totient is φ = 334008720.

The previous prime is 668017423. The next prime is 668017517. The reversal of 668017442 is 244710866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 244710866 = 2 ⋅122355433.

It can be written as a sum of positive squares in only one way, i.e., 434263921 + 233753521 = 20839^2 + 15289^2 .

It is a junction number, because it is equal to n+sod(n) for n = 668017396 and 668017405.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167004359 + ... + 167004362.

Almost surely, 2^668017442 is an apocalyptic number.

668017442 is a deficient number, since it is larger than the sum of its proper divisors (334008724).

668017442 is a wasteful number, since it uses less digits than its factorization.

668017442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334008723.

The product of its (nonzero) digits is 64512, while the sum is 38.

The square root of 668017442 is about 25846.0333900581. The cubic root of 668017442 is about 874.1700721735.

The spelling of 668017442 in words is "six hundred sixty-eight million, seventeen thousand, four hundred forty-two".