25205555555 has 4 divisors (see below), whose sum is σ = 30246666672. Its totient is φ = 20164444440.

The previous prime is 25205555533. The next prime is 25205555579. The reversal of 25205555555 is 55555550252.

It is a happy number.

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

It is not a de Polignac number, because 25205555555 - 2²⁶ = 25138446691 is a prime.

It is a Duffinian number.

25205555555 is a modest number, since divided by 555555 gives 25205 as remainder.

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, 2520555551 + ... + 2520555560.

It is an arithmetic number, because the mean of its divisors is an integer number (7561666668).

Almost surely, 2^25205555555 is an apocalyptic number.

25205555555 is a deficient number, since it is larger than the sum of its proper divisors (5041111117).

25205555555 is an equidigital number, since it uses as much as digits as its factorization.

25205555555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5041111116.

The product of its (nonzero) digits is 1562500, while the sum is 44.

The spelling of 25205555555 in words is "twenty-five billion, two hundred five million, five hundred fifty-five thousand, five hundred fifty-five".