25778491 has 2 divisors, whose sum is σ = 25778492. Its totient is φ = 25778490.

The previous prime is 25778461. The next prime is 25778507. The reversal of 25778491 is 19487752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25778491 - 2¹⁵ = 25745723 is a prime.

It is not a weakly prime, because it can be changed into another prime (25778461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12889245 + 12889246.

It is an arithmetic number, because the mean of its divisors is an integer number (12889246).

Almost surely, 2^25778491 is an apocalyptic number.

25778491 is a deficient number, since it is larger than the sum of its proper divisors (1).

25778491 is an equidigital number, since it uses as much as digits as its factorization.

25778491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141120, while the sum is 43.

The square root of 25778491 is about 5077.2523080895. The cubic root of 25778491 is about 295.4058991696.

The spelling of 25778491 in words is "twenty-five million, seven hundred seventy-eight thousand, four hundred ninety-one".