25802565457 has 8 divisors (see below), whose sum is σ = 25940755784. Its totient is φ = 25664421888.

The previous prime is 25802565443. The next prime is 25802565461. The reversal of 25802565457 is 75456520852.

It can be written as a sum of positive squares in 4 ways, for example, as 2651117121 + 23151448336 = 51489^2 + 152156^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25802565457 - 2¹⁵ = 25802532689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25802565457.

It is not an unprimeable number, because it can be changed into a prime (25802565557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2069113 + ... + 2081545.

It is an arithmetic number, because the mean of its divisors is an integer number (3242594473).

Almost surely, 2^25802565457 is an apocalyptic number.

It is an amenable number.

25802565457 is a deficient number, since it is larger than the sum of its proper divisors (138190327).

25802565457 is a wasteful number, since it uses less digits than its factorization.

25802565457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23379.

The product of its (nonzero) digits is 3360000, while the sum is 49.

The spelling of 25802565457 in words is "twenty-five billion, eight hundred two million, five hundred sixty-five thousand, four hundred fifty-seven".