25664849309 has 4 divisors (see below), whose sum is σ = 27998017440. Its totient is φ = 23331681180.

The previous prime is 25664849303. The next prime is 25664849333. The reversal of 25664849309 is 90394846652.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-25664849309 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 (25664849303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1166584049 + ... + 1166584070.

It is an arithmetic number, because the mean of its divisors is an integer number (6999504360).

Almost surely, 2^25664849309 is an apocalyptic number.

It is an amenable number.

25664849309 is a deficient number, since it is larger than the sum of its proper divisors (2333168131).

25664849309 is a wasteful number, since it uses less digits than its factorization.

25664849309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333168130.

The product of its (nonzero) digits is 11197440, while the sum is 56.

The spelling of 25664849309 in words is "twenty-five billion, six hundred sixty-four million, eight hundred forty-nine thousand, three hundred nine".