664350623 has 4 divisors (see below), whose sum is σ = 668750448. Its totient is φ = 659950800.

The previous prime is 664350613. The next prime is 664350641. The reversal of 664350623 is 326053466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 326053466 = 2 ⋅163026733.

It is a cyclic number.

It is not a de Polignac number, because 664350623 - 2¹⁰ = 664349599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664350613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2199686 + ... + 2199987.

It is an arithmetic number, because the mean of its divisors is an integer number (167187612).

Almost surely, 2^664350623 is an apocalyptic number.

664350623 is a deficient number, since it is larger than the sum of its proper divisors (4399825).

664350623 is a wasteful number, since it uses less digits than its factorization.

664350623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4399824.

The product of its (nonzero) digits is 77760, while the sum is 35.

The square root of 664350623 is about 25774.9999612027. Note that the first 4 decimals coincide. The cubic root of 664350623 is about 872.5676657346.

The spelling of 664350623 in words is "six hundred sixty-four million, three hundred fifty thousand, six hundred twenty-three".