666666045 has 30 divisors (see below), whose sum is σ = 1195992798. Its totient is φ = 355278096.

The previous prime is 666666031. The next prime is 666666071. The reversal of 666666045 is 540666666.

It can be written as a sum of positive squares in only one way, i.e., 533332836 + 133333209 = 23094^2 + 11547^2 .

It is not a de Polignac number, because 666666045 - 2⁴ = 666666029 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 518974 + ... + 520256.

Almost surely, 2^666666045 is an apocalyptic number.

It is an amenable number.

666666045 is a deficient number, since it is larger than the sum of its proper divisors (529326753).

666666045 is an frugal number, since it uses more digits than its factorization.

666666045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2583 (or 1291 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The square root of 666666045 is about 25819.8769361901. The cubic root of 666666045 is about 873.5801931983.

Multiplying 666666045 by its sum of digits (45), we get a square (29999972025 = 173205²).

666666045 divided by its sum of digits (45) gives a square (14814801 = 3849²).

Multiplying 666666045 by its product of nonzero digits (933120), we get a square (622079419910400 = 24941520²).

The spelling of 666666045 in words is "six hundred sixty-six million, six hundred sixty-six thousand, forty-five".