25724634385 has 4 divisors (see below), whose sum is σ = 30869561268. Its totient is φ = 20579707504.

The previous prime is 25724634361. The next prime is 25724634401. The reversal of 25724634385 is 58343642752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16302437761 + 9422196624 = 127681^2 + 97068^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25724634385 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 2572463434 + ... + 2572463443.

It is an arithmetic number, because the mean of its divisors is an integer number (7717390317).

Almost surely, 2^25724634385 is an apocalyptic number.

It is an amenable number.

25724634385 is a deficient number, since it is larger than the sum of its proper divisors (5144926883).

25724634385 is an equidigital number, since it uses as much as digits as its factorization.

25724634385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5144926882.

The product of its digits is 4838400, while the sum is 49.

The spelling of 25724634385 in words is "twenty-five billion, seven hundred twenty-four million, six hundred thirty-four thousand, three hundred eighty-five".