668067919 has 4 divisors (see below), whose sum is σ = 670244344. Its totient is φ = 665891496.

The previous prime is 668067871. The next prime is 668067929. The reversal of 668067919 is 919760866.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668067919 is a prime.

It is a super-2 number, since 2×668067919² = 892629488793981122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668067929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1087752 + ... + 1088365.

It is an arithmetic number, because the mean of its divisors is an integer number (167561086).

Almost surely, 2^668067919 is an apocalyptic number.

668067919 is a deficient number, since it is larger than the sum of its proper divisors (2176425).

668067919 is a wasteful number, since it uses less digits than its factorization.

668067919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2176424.

The product of its (nonzero) digits is 979776, while the sum is 52.

The square root of 668067919 is about 25847.0098657466. The cubic root of 668067919 is about 874.1920897480.

The spelling of 668067919 in words is "six hundred sixty-eight million, sixty-seven thousand, nine hundred nineteen".