664863845 has 8 divisors (see below), whose sum is σ = 797975064. Its totient is φ = 531798784.

The previous prime is 664863821. The next prime is 664863917. The reversal of 664863845 is 548368466.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 401321089 + 263542756 = 20033^2 + 16234^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664863845 - 2¹⁴ = 664847461 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664863793 and 664863802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49937 + ... + 61833.

It is an arithmetic number, because the mean of its divisors is an integer number (99746883).

Almost surely, 2^664863845 is an apocalyptic number.

It is an amenable number.

664863845 is a deficient number, since it is larger than the sum of its proper divisors (133111219).

664863845 is a wasteful number, since it uses less digits than its factorization.

664863845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23079.

The product of its digits is 3317760, while the sum is 50.

The square root of 664863845 is about 25784.9538490958. The cubic root of 664863845 is about 872.7922989529.

The spelling of 664863845 in words is "six hundred sixty-four million, eight hundred sixty-three thousand, eight hundred forty-five".