25561218705 has 64 divisors (see below), whose sum is σ = 47345264640. Its totient is φ = 11653452800.

The previous prime is 25561218703. The next prime is 25561218763. The reversal of 25561218705 is 50781216552.

It is not a de Polignac number, because 25561218705 - 2¹ = 25561218703 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25561218701) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 166825 + ... + 280985.

It is an arithmetic number, because the mean of its divisors is an integer number (739769760).

Almost surely, 2^25561218705 is an apocalyptic number.

It is an amenable number.

25561218705 is a deficient number, since it is larger than the sum of its proper divisors (21784045935).

25561218705 is a wasteful number, since it uses less digits than its factorization.

25561218705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114262.

The product of its (nonzero) digits is 168000, while the sum is 42.

The spelling of 25561218705 in words is "twenty-five billion, five hundred sixty-one million, two hundred eighteen thousand, seven hundred five".