25212108505 has 4 divisors (see below), whose sum is σ = 30254530212. Its totient is φ = 20169686800.

The previous prime is 25212108499. The next prime is 25212108511. The reversal of 25212108505 is 50580121252.

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

It is an interprime number because it is at equal distance from previous prime (25212108499) and next prime (25212108511).

It can be written as a sum of positive squares in 2 ways, for example, as 13794972304 + 11417136201 = 117452^2 + 106851^2 .

It is not a de Polignac number, because 25212108505 - 2³ = 25212108497 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2521210846 + ... + 2521210855.

It is an arithmetic number, because the mean of its divisors is an integer number (7563632553).

Almost surely, 2^25212108505 is an apocalyptic number.

It is an amenable number.

25212108505 is a deficient number, since it is larger than the sum of its proper divisors (5042421707).

25212108505 is an equidigital number, since it uses as much as digits as its factorization.

25212108505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5042421706.

The product of its (nonzero) digits is 8000, while the sum is 31.

Adding to 25212108505 its reverse (50580121252), we get a palindrome (75792229757).

The spelling of 25212108505 in words is "twenty-five billion, two hundred twelve million, one hundred eight thousand, five hundred five".