25780334581 has 2 divisors, whose sum is σ = 25780334582. Its totient is φ = 25780334580.

The previous prime is 25780334551. The next prime is 25780334597. The reversal of 25780334581 is 18543308752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13140953956 + 12639380625 = 114634^2 + 112425^2 .

It is a cyclic number.

It is not a de Polignac number, because 25780334581 - 2⁵ = 25780334549 is a prime.

It is a super-4 number, since 4×25780334581⁴ (a number of 43 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25780334501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12890167290 + 12890167291.

It is an arithmetic number, because the mean of its divisors is an integer number (12890167291).

Almost surely, 2^25780334581 is an apocalyptic number.

It is an amenable number.

25780334581 is a deficient number, since it is larger than the sum of its proper divisors (1).

25780334581 is an equidigital number, since it uses as much as digits as its factorization.

25780334581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 806400, while the sum is 46.

The spelling of 25780334581 in words is "twenty-five billion, seven hundred eighty million, three hundred thirty-four thousand, five hundred eighty-one".