25440397 has 2 divisors, whose sum is σ = 25440398. Its totient is φ = 25440396.

The previous prime is 25440379. The next prime is 25440403. The reversal of 25440397 is 79304452.

Together with previous prime (25440379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17065161 + 8375236 = 4131^2 + 2894^2 .

It is a cyclic number.

It is not a de Polignac number, because 25440397 - 2¹¹ = 25438349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25440307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12720198 + 12720199.

It is an arithmetic number, because the mean of its divisors is an integer number (12720199).

Almost surely, 2^25440397 is an apocalyptic number.

It is an amenable number.

25440397 is a deficient number, since it is larger than the sum of its proper divisors (1).

25440397 is an equidigital number, since it uses as much as digits as its factorization.

25440397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 25440397 is about 5043.8474401988. The cubic root of 25440397 is about 294.1087608774.

The spelling of 25440397 in words is "twenty-five million, four hundred forty thousand, three hundred ninety-seven".