668928429 has 16 divisors (see below), whose sum is σ = 1067236800. Its totient is φ = 411648048.

The previous prime is 668928401. The next prime is 668928433. The reversal of 668928429 is 924829866.

It is a happy number.

It is not a de Polignac number, because 668928429 - 2⁷ = 668928301 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668928479) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 952539 + ... + 953240.

It is an arithmetic number, because the mean of its divisors is an integer number (66702300).

Almost surely, 2^668928429 is an apocalyptic number.

It is an amenable number.

668928429 is a deficient number, since it is larger than the sum of its proper divisors (398308371).

668928429 is a wasteful number, since it uses less digits than its factorization.

668928429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1905801 (or 1905795 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The square root of 668928429 is about 25863.6507283871. The cubic root of 668928429 is about 874.5672653172.

The spelling of 668928429 in words is "six hundred sixty-eight million, nine hundred twenty-eight thousand, four hundred twenty-nine".