25878738385781 has 2 divisors, whose sum is σ = 25878738385782. Its totient is φ = 25878738385780.

The previous prime is 25878738385693. The next prime is 25878738385849. The reversal of 25878738385781 is 18758383787852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24429986728900 + 1448751656881 = 4942670^2 + 1203641^2 .

It is a cyclic number.

It is not a de Polignac number, because 25878738385781 - 2²² = 25878734191477 is a prime.

It is a super-2 number, since 2×25878738385781² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25878738385696 and 25878738385705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25878738382781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12939369192890 + 12939369192891.

It is an arithmetic number, because the mean of its divisors is an integer number (12939369192891).

Almost surely, 2^{25878738385781} is an apocalyptic number.

It is an amenable number.

25878738385781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25878738385781 is an equidigital number, since it uses as much as digits as its factorization.

25878738385781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5057740800, while the sum is 80.

The spelling of 25878738385781 in words is "twenty-five trillion, eight hundred seventy-eight billion, seven hundred thirty-eight million, three hundred eighty-five thousand, seven hundred eighty-one".