666564455 has 4 divisors (see below), whose sum is σ = 799877352. Its totient is φ = 533251560.

The previous prime is 666564443. The next prime is 666564491. The reversal of 666564455 is 554465666.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 666564455 - 2⁴ = 666564439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66656441 + ... + 66656450.

It is an arithmetic number, because the mean of its divisors is an integer number (199969338).

Almost surely, 2^666564455 is an apocalyptic number.

666564455 is a deficient number, since it is larger than the sum of its proper divisors (133312897).

666564455 is a wasteful number, since it uses less digits than its factorization.

666564455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133312896.

The product of its digits is 2592000, while the sum is 47.

The square root of 666564455 is about 25817.9095784302. The cubic root of 666564455 is about 873.5358173968.

The spelling of 666564455 in words is "six hundred sixty-six million, five hundred sixty-four thousand, four hundred fifty-five".