25646412849 has 4 divisors (see below), whose sum is σ = 34195217136. Its totient is φ = 17097608564.

The previous prime is 25646412839. The next prime is 25646412851. The reversal of 25646412849 is 94821464652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25646412849 - 2¹⁶ = 25646347313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25646412839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4274402139 + ... + 4274402144.

It is an arithmetic number, because the mean of its divisors is an integer number (8548804284).

Almost surely, 2^25646412849 is an apocalyptic number.

It is an amenable number.

25646412849 is a deficient number, since it is larger than the sum of its proper divisors (8548804287).

25646412849 is an equidigital number, since it uses as much as digits as its factorization.

25646412849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8548804286.

The product of its digits is 3317760, while the sum is 51.

The spelling of 25646412849 in words is "twenty-five billion, six hundred forty-six million, four hundred twelve thousand, eight hundred forty-nine".