668440423 has 8 divisors (see below), whose sum is σ = 764416160. Its totient is φ = 572585760.

The previous prime is 668440411. The next prime is 668440453. The reversal of 668440423 is 324044866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 668440423 - 2⁹ = 668439911 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 (668440453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18108 + ... + 40801.

It is an arithmetic number, because the mean of its divisors is an integer number (95552020).

Almost surely, 2^668440423 is an apocalyptic number.

668440423 is a deficient number, since it is larger than the sum of its proper divisors (95975737).

668440423 is a wasteful number, since it uses less digits than its factorization.

668440423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60537.

The product of its (nonzero) digits is 110592, while the sum is 37.

The square root of 668440423 is about 25854.2148014594. The cubic root of 668440423 is about 874.3545380739.

The spelling of 668440423 in words is "six hundred sixty-eight million, four hundred forty thousand, four hundred twenty-three".