25887781 has 2 divisors, whose sum is σ = 25887782. Its totient is φ = 25887780.

The previous prime is 25887779. The next prime is 25887791. The reversal of 25887781 is 18778852.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25411681 + 476100 = 5041^2 + 690^2 .

It is a cyclic number.

It is not a de Polignac number, because 25887781 - 2¹ = 25887779 is a prime.

It is a super-2 number, since 2×25887781² = 1340354410207922, which contains 22 as substring.

Together with 25887779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25887751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12943890 + 12943891.

It is an arithmetic number, because the mean of its divisors is an integer number (12943891).

Almost surely, 2^25887781 is an apocalyptic number.

It is an amenable number.

25887781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25887781 is an equidigital number, since it uses as much as digits as its factorization.

25887781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 250880, while the sum is 46.

The square root of 25887781 is about 5088.0036360050. The cubic root of 25887781 is about 295.8227763386.

The spelling of 25887781 in words is "twenty-five million, eight hundred eighty-seven thousand, seven hundred eighty-one".