25691779 has 2 divisors, whose sum is σ = 25691780. Its totient is φ = 25691778.

The previous prime is 25691773. The next prime is 25691791. The reversal of 25691779 is 97719652.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25691779 - 2¹⁹ = 25167491 is a prime.

It is not a weakly prime, because it can be changed into another prime (25691773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12845889 + 12845890.

It is an arithmetic number, because the mean of its divisors is an integer number (12845890).

Almost surely, 2^25691779 is an apocalyptic number.

25691779 is a deficient number, since it is larger than the sum of its proper divisors (1).

25691779 is an equidigital number, since it uses as much as digits as its factorization.

25691779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 238140, while the sum is 46.

The square root of 25691779 is about 5068.7058506092. The cubic root of 25691779 is about 295.0743047528.

The spelling of 25691779 in words is "twenty-five million, six hundred ninety-one thousand, seven hundred seventy-nine".