669668145 has 16 divisors (see below), whose sum is σ = 1108416960. Its totient is φ = 344840384.

The previous prime is 669668141. The next prime is 669668179. The reversal of 669668145 is 541866966.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 669668145 - 2² = 669668141 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (669668141) 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, 769299 + ... + 770168.

It is an arithmetic number, because the mean of its divisors is an integer number (69276060).

Almost surely, 2^669668145 is an apocalyptic number.

It is an amenable number.

669668145 is a deficient number, since it is larger than the sum of its proper divisors (438748815).

669668145 is a wasteful number, since it uses less digits than its factorization.

669668145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539504.

The product of its digits is 1866240, while the sum is 51.

The square root of 669668145 is about 25877.9470785455. The cubic root of 669668145 is about 874.8895185677.

The spelling of 669668145 in words is "six hundred sixty-nine million, six hundred sixty-eight thousand, one hundred forty-five".