25784981 has 2 divisors, whose sum is σ = 25784982. Its totient is φ = 25784980.

The previous prime is 25784959. The next prime is 25784989. The reversal of 25784981 is 18948752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15602500 + 10182481 = 3950^2 + 3191^2 .

It is a cyclic number.

It is not a de Polignac number, because 25784981 - 2¹⁴ = 25768597 is a prime.

It is a super-2 number, since 2×25784981² = 1329730490340722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25784989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12892490 + 12892491.

It is an arithmetic number, because the mean of its divisors is an integer number (12892491).

Almost surely, 2^25784981 is an apocalyptic number.

It is an amenable number.

25784981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25784981 is an equidigital number, since it uses as much as digits as its factorization.

25784981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 44.

The square root of 25784981 is about 5077.8913930883. The cubic root of 25784981 is about 295.4306875797.

The spelling of 25784981 in words is "twenty-five million, seven hundred eighty-four thousand, nine hundred eighty-one".