666624443 has 4 divisors (see below), whose sum is σ = 701709960. Its totient is φ = 631538928.

The previous prime is 666624437. The next prime is 666624487. The reversal of 666624443 is 344426666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 344426666 = 2 ⋅172213333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666624443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666624443.

It is not an unprimeable number, because it can be changed into a prime (666623443) 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, 17542730 + ... + 17542767.

It is an arithmetic number, because the mean of its divisors is an integer number (175427490).

Almost surely, 2^666624443 is an apocalyptic number.

666624443 is a deficient number, since it is larger than the sum of its proper divisors (35085517).

666624443 is a wasteful number, since it uses less digits than its factorization.

666624443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35085516.

The product of its digits is 497664, while the sum is 41.

The square root of 666624443 is about 25819.0713039799. The cubic root of 666624443 is about 873.5620214617.

The spelling of 666624443 in words is "six hundred sixty-six million, six hundred twenty-four thousand, four hundred forty-three".