666557027 has 4 divisors (see below), whose sum is σ = 667566096. Its totient is φ = 665547960.

The previous prime is 666556987. The next prime is 666557051. The reversal of 666557027 is 720755666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 720755666 = 2 ⋅360377833.

It is a cyclic number.

It is not a de Polignac number, because 666557027 - 2⁶ = 666556963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666557327) 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, 503543 + ... + 504864.

It is an arithmetic number, because the mean of its divisors is an integer number (166891524).

Almost surely, 2^666557027 is an apocalyptic number.

666557027 is a deficient number, since it is larger than the sum of its proper divisors (1009069).

666557027 is a wasteful number, since it uses less digits than its factorization.

666557027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1009068.

The product of its (nonzero) digits is 529200, while the sum is 44.

The square root of 666557027 is about 25817.7657243999. The cubic root of 666557027 is about 873.5325725753.

The spelling of 666557027 in words is "six hundred sixty-six million, five hundred fifty-seven thousand, twenty-seven".