668894029 has 4 divisors (see below), whose sum is σ = 686972284. Its totient is φ = 650815776.

The previous prime is 668894011. The next prime is 668894047. The reversal of 668894029 is 920498866.

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

It is an interprime number because it is at equal distance from previous prime (668894011) and next prime (668894047).

It can be written as a sum of positive squares in 2 ways, for example, as 352125225 + 316768804 = 18765^2 + 17798^2 .

It is a cyclic number.

It is not a de Polignac number, because 668894029 - 2¹¹ = 668891981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668894729) 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, 9039072 + ... + 9039145.

It is an arithmetic number, because the mean of its divisors is an integer number (171743071).

Almost surely, 2^668894029 is an apocalyptic number.

It is an amenable number.

668894029 is a deficient number, since it is larger than the sum of its proper divisors (18078255).

668894029 is a wasteful number, since it uses less digits than its factorization.

668894029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18078254.

The product of its (nonzero) digits is 1492992, while the sum is 52.

The square root of 668894029 is about 25862.9856938444. The cubic root of 668894029 is about 874.5522733647.

The spelling of 668894029 in words is "six hundred sixty-eight million, eight hundred ninety-four thousand, twenty-nine".