25666803457 has 4 divisors (see below), whose sum is σ = 25681497136. Its totient is φ = 25652109780.

The previous prime is 25666803413. The next prime is 25666803509. The reversal of 25666803457 is 75430866652.

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 25666803457 - 2¹¹ = 25666801409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25666803857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7344219 + ... + 7347712.

It is an arithmetic number, because the mean of its divisors is an integer number (6420374284).

Almost surely, 2^25666803457 is an apocalyptic number.

It is an amenable number.

25666803457 is a deficient number, since it is larger than the sum of its proper divisors (14693679).

25666803457 is a wasteful number, since it uses less digits than its factorization.

25666803457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14693678.

The product of its (nonzero) digits is 7257600, while the sum is 52.

The spelling of 25666803457 in words is "twenty-five billion, six hundred sixty-six million, eight hundred three thousand, four hundred fifty-seven".