25778551 has 2 divisors, whose sum is σ = 25778552. Its totient is φ = 25778550.

The previous prime is 25778549. The next prime is 25778591. The reversal of 25778551 is 15587752.

It is an a-pointer prime, because the next prime (25778591) can be obtained adding 25778551 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25778551 - 2¹ = 25778549 is a prime.

Together with 25778549, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25778591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12889275 + 12889276.

It is an arithmetic number, because the mean of its divisors is an integer number (12889276).

Almost surely, 2^25778551 is an apocalyptic number.

25778551 is a deficient number, since it is larger than the sum of its proper divisors (1).

25778551 is an equidigital number, since it uses as much as digits as its factorization.

25778551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98000, while the sum is 40.

The square root of 25778551 is about 5077.2582167938. The cubic root of 25778551 is about 295.4061283574.

The spelling of 25778551 in words is "twenty-five million, seven hundred seventy-eight thousand, five hundred fifty-one".