666634459 has 4 divisors (see below), whose sum is σ = 666850104. Its totient is φ = 666418816.

The previous prime is 666634433. The next prime is 666634487. The reversal of 666634459 is 954436666.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 666634459 - 2¹⁹ = 666110171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666634429) 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, 103117 + ... + 109390.

It is an arithmetic number, because the mean of its divisors is an integer number (166712526).

Almost surely, 2^666634459 is an apocalyptic number.

666634459 is a deficient number, since it is larger than the sum of its proper divisors (215645).

666634459 is a wasteful number, since it uses less digits than its factorization.

666634459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215644.

The product of its digits is 2799360, while the sum is 49.

The square root of 666634459 is about 25819.2652683999. The cubic root of 666634459 is about 873.5663965155.

The spelling of 666634459 in words is "six hundred sixty-six million, six hundred thirty-four thousand, four hundred fifty-nine".