25604506264661 has 4 divisors (see below), whose sum is σ = 27110653692012. Its totient is φ = 24098358837312.

The previous prime is 25604506264639. The next prime is 25604506264681. The reversal of 25604506264661 is 16646260540652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18702294898225 + 6902211366436 = 4324615^2 + 2627206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25604506264661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25604506264621) 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, 753073713650 + ... + 753073713683.

It is an arithmetic number, because the mean of its divisors is an integer number (6777663423003).

Almost surely, 2^{25604506264661} is an apocalyptic number.

It is an amenable number.

25604506264661 is a deficient number, since it is larger than the sum of its proper divisors (1506147427351).

25604506264661 is a wasteful number, since it uses less digits than its factorization.

25604506264661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1506147427350.

The product of its (nonzero) digits is 12441600, while the sum is 53.

The spelling of 25604506264661 in words is "twenty-five trillion, six hundred four billion, five hundred six million, two hundred sixty-four thousand, six hundred sixty-one".