640104004225 has 27 divisors (see below), whose sum is σ = 923357761347. Its totient is φ = 438909258480.

The previous prime is 640104004187. The next prime is 640104004261. The reversal of 640104004225 is 522400401046.

The square root of 640104004225 is 800065.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 230437441521 + 409666562704 = 480039^2 + 640052^2 .

It is not a de Polignac number, because 640104004225 - 2²³ = 640095615617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640104004193 and 640104004202.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 27990846 + ... + 28013704.

Almost surely, 2^640104004225 is an apocalyptic number.

640104004225 is the 800065-th square number.

640104004225 is the 400033-rd centered octagonal number.

It is an amenable number.

640104004225 is a deficient number, since it is larger than the sum of its proper divisors (283253757122).

640104004225 is an frugal number, since it uses more digits than its factorization.

640104004225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45742 (or 22871 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 28.

The spelling of 640104004225 in words is "six hundred forty billion, one hundred four million, four thousand, two hundred twenty-five".