668619899 has 8 divisors (see below), whose sum is σ = 710780880. Its totient is φ = 627156000.

The previous prime is 668619827. The next prime is 668619929. The reversal of 668619899 is 998916866.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668619899 is a prime.

668619899 is a strobogrammatic number because it is the same when read upside-down.

It is not an unprimeable number, because it can be changed into a prime (668613899) 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, 172292 + ... + 176129.

It is an arithmetic number, because the mean of its divisors is an integer number (88847610).

Almost surely, 2^668619899 is an apocalyptic number.

668619899 is a deficient number, since it is larger than the sum of its proper divisors (42160981).

668619899 is a wasteful number, since it uses less digits than its factorization.

668619899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348541.

The product of its digits is 10077696, while the sum is 62.

The square root of 668619899 is about 25857.6854919384. The cubic root of 668619899 is about 874.4327856918.

The spelling of 668619899 in words is "six hundred sixty-eight million, six hundred nineteen thousand, eight hundred ninety-nine".