25691791 has 2 divisors, whose sum is σ = 25691792. Its totient is φ = 25691790.

The previous prime is 25691779. The next prime is 25691807. The reversal of 25691791 is 19719652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25691791 - 2¹⁹ = 25167503 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25691891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12845895 + 12845896.

It is an arithmetic number, because the mean of its divisors is an integer number (12845896).

Almost surely, 2^25691791 is an apocalyptic number.

25691791 is a deficient number, since it is larger than the sum of its proper divisors (1).

25691791 is an equidigital number, since it uses as much as digits as its factorization.

25691791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 40.

The square root of 25691791 is about 5068.7070343432. The cubic root of 25691791 is about 295.0743506934.

The spelling of 25691791 in words is "twenty-five million, six hundred ninety-one thousand, seven hundred ninety-one".