25769981 has 2 divisors, whose sum is σ = 25769982. Its totient is φ = 25769980.

The previous prime is 25769971. The next prime is 25770007. The reversal of 25769981 is 18996752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25664356 + 105625 = 5066^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 25769981 - 2⁶ = 25769917 is a prime.

It is a super-2 number, since 2×25769981² = 1328183841480722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25769941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12884990 + 12884991.

It is an arithmetic number, because the mean of its divisors is an integer number (12884991).

Almost surely, 2^25769981 is an apocalyptic number.

It is an amenable number.

25769981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25769981 is an equidigital number, since it uses as much as digits as its factorization.

25769981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 47.

The square root of 25769981 is about 5076.4141871995. The cubic root of 25769981 is about 295.3733891094.

The spelling of 25769981 in words is "twenty-five million, seven hundred sixty-nine thousand, nine hundred eighty-one".