25844656513 has 4 divisors (see below), whose sum is σ = 27832707028. Its totient is φ = 23856606000.

The previous prime is 25844656499. The next prime is 25844656517. The reversal of 25844656513 is 31565644852.

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 7636662544 + 18207993969 = 87388^2 + 134937^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25844656513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25844656517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 994025238 + ... + 994025263.

It is an arithmetic number, because the mean of its divisors is an integer number (6958176757).

Almost surely, 2^25844656513 is an apocalyptic number.

It is an amenable number.

25844656513 is a deficient number, since it is larger than the sum of its proper divisors (1988050515).

25844656513 is a wasteful number, since it uses less digits than its factorization.

25844656513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1988050514.

The product of its digits is 3456000, while the sum is 49.

The spelling of 25844656513 in words is "twenty-five billion, eight hundred forty-four million, six hundred fifty-six thousand, five hundred thirteen".