25780009 has 4 divisors (see below), whose sum is σ = 26476804. Its totient is φ = 25083216.

The previous prime is 25779997. The next prime is 25780019. The reversal of 25780009 is 90008752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19669225 + 6110784 = 4435^2 + 2472^2 .

It is a cyclic number.

It is not a de Polignac number, because 25780009 - 2⁵ = 25779977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25780019) 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 in 3 ways as a sum of consecutive naturals, for example, 348342 + ... + 348415.

It is an arithmetic number, because the mean of its divisors is an integer number (6619201).

Almost surely, 2^25780009 is an apocalyptic number.

It is an amenable number.

25780009 is a deficient number, since it is larger than the sum of its proper divisors (696795).

25780009 is an equidigital number, since it uses as much as digits as its factorization.

25780009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696794.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 25780009 is about 5077.4017961946. The cubic root of 25780009 is about 295.4116975095.

The spelling of 25780009 in words is "twenty-five million, seven hundred eighty thousand, nine".