668466889 has 4 divisors (see below), whose sum is σ = 668529556. Its totient is φ = 668404224.

The previous prime is 668466881. The next prime is 668466923. The reversal of 668466889 is 988664866.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 295668025 + 372798864 = 17195^2 + 19308^2 .

It is a cyclic number.

It is not a de Polignac number, because 668466889 - 2³ = 668466881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668466881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10884 + ... + 38149.

It is an arithmetic number, because the mean of its divisors is an integer number (167132389).

Almost surely, 2^668466889 is an apocalyptic number.

It is an amenable number.

668466889 is a deficient number, since it is larger than the sum of its proper divisors (62667).

668466889 is a wasteful number, since it uses less digits than its factorization.

668466889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62666.

The product of its digits is 23887872, while the sum is 61.

The square root of 668466889 is about 25854.7266278334. The cubic root of 668466889 is about 874.3660775525.

The spelling of 668466889 in words is "six hundred sixty-eight million, four hundred sixty-six thousand, eight hundred eighty-nine".