25805585506 has 16 divisors (see below), whose sum is σ = 41284512216. Its totient is φ = 12055161856.

The previous prime is 25805585473. The next prime is 25805585513. The reversal of 25805585506 is 60558550852.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 23032615225 + 2772970281 = 151765^2 + 52659^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25805585506.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2765371 + ... + 2774686.

Almost surely, 2^25805585506 is an apocalyptic number.

25805585506 is a deficient number, since it is larger than the sum of its proper divisors (15478926710).

25805585506 is a wasteful number, since it uses less digits than its factorization.

25805585506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5540213.

The product of its (nonzero) digits is 2400000, while the sum is 49.

The spelling of 25805585506 in words is "twenty-five billion, eight hundred five million, five hundred eighty-five thousand, five hundred six".