25568969409 has 45 divisors (see below), whose sum is σ = 38787203763. Its totient is φ = 16785977328.

The previous prime is 25568969407. The next prime is 25568969411. The reversal of 25568969409 is 90496986552.

The square root of 25568969409 is 159903.

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

25568969409 is a `hidden beast` number, since 2 + 5 + 568 + 9 + 69 + 4 + 0 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (25568969407) and next prime (25568969411).

It can be written as a sum of positive squares in only one way, i.e., 17821449009 + 7747520400 = 133497^2 + 88020^2 .

It is not a de Polignac number, because 25568969409 - 2¹ = 25568969407 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25568969407) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 156864762 + ... + 156864924.

Almost surely, 2^25568969409 is an apocalyptic number.

25568969409 is the 159903-rd square number.

25568969409 is the 79952-nd centered octagonal number.

It is an amenable number.

25568969409 is a deficient number, since it is larger than the sum of its proper divisors (13218234354).

25568969409 is an frugal number, since it uses more digits than its factorization.

25568969409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 63.

The spelling of 25568969409 in words is "twenty-five billion, five hundred sixty-eight million, nine hundred sixty-nine thousand, four hundred nine".