25250025781 has 2 divisors, whose sum is σ = 25250025782. Its totient is φ = 25250025780.

The previous prime is 25250025769. The next prime is 25250025799. The reversal of 25250025781 is 18752005252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16793568100 + 8456457681 = 129590^2 + 91959^2 .

It is a cyclic number.

It is not a de Polignac number, because 25250025781 - 2⁷ = 25250025653 is a prime.

It is a super-2 number, since 2×25250025781² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25250025781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25250025751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12625012890 + 12625012891.

It is an arithmetic number, because the mean of its divisors is an integer number (12625012891).

Almost surely, 2^25250025781 is an apocalyptic number.

It is an amenable number.

25250025781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25250025781 is an equidigital number, since it uses as much as digits as its factorization.

25250025781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56000, while the sum is 37.

The spelling of 25250025781 in words is "twenty-five billion, two hundred fifty million, twenty-five thousand, seven hundred eighty-one".