25665551455 has 4 divisors (see below), whose sum is σ = 30798661752. Its totient is φ = 20532441160.

The previous prime is 25665551453. The next prime is 25665551507. The reversal of 25665551455 is 55415556652.

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

It is not a de Polignac number, because 25665551455 - 2¹ = 25665551453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25665551399 and 25665551408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25665551453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2566555141 + ... + 2566555150.

It is an arithmetic number, because the mean of its divisors is an integer number (7699665438).

Almost surely, 2^25665551455 is an apocalyptic number.

25665551455 is a deficient number, since it is larger than the sum of its proper divisors (5133110297).

25665551455 is an equidigital number, since it uses as much as digits as its factorization.

25665551455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5133110296.

The product of its digits is 4500000, while the sum is 49.

The spelling of 25665551455 in words is "twenty-five billion, six hundred sixty-five million, five hundred fifty-one thousand, four hundred fifty-five".