668405599 has 8 divisors (see below), whose sum is σ = 697968000. Its totient is φ = 638885016.

The previous prime is 668405561. The next prime is 668405611. The reversal of 668405599 is 995504866.

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 668405599 - 2¹¹ = 668403551 is a prime.

It is a super-3 number, since 3×668405599³ (a number of 27 digits) contains 333 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 (668405299) 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, 24784 + ... + 44170.

It is an arithmetic number, because the mean of its divisors is an integer number (87246000).

Almost surely, 2^668405599 is an apocalyptic number.

668405599 is a deficient number, since it is larger than the sum of its proper divisors (29562401).

668405599 is a wasteful number, since it uses less digits than its factorization.

668405599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20909.

The product of its (nonzero) digits is 2332800, while the sum is 52.

The square root of 668405599 is about 25853.5413241591. The cubic root of 668405599 is about 874.3393539477.

The spelling of 668405599 in words is "six hundred sixty-eight million, four hundred five thousand, five hundred ninety-nine".