25218579109 has 4 divisors (see below), whose sum is σ = 25349245516. Its totient is φ = 25087912704.

The previous prime is 25218579083. The next prime is 25218579131. The reversal of 25218579109 is 90197581252.

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 14392800900 + 10825778209 = 119970^2 + 104047^2 .

It is a cyclic number.

It is not a de Polignac number, because 25218579109 - 2⁵ = 25218579077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25218570109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65332914 + ... + 65333299.

It is an arithmetic number, because the mean of its divisors is an integer number (6337311379).

Almost surely, 2^25218579109 is an apocalyptic number.

It is an amenable number.

25218579109 is a deficient number, since it is larger than the sum of its proper divisors (130666407).

25218579109 is a wasteful number, since it uses less digits than its factorization.

25218579109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130666406.

The product of its (nonzero) digits is 453600, while the sum is 49.

The spelling of 25218579109 in words is "twenty-five billion, two hundred eighteen million, five hundred seventy-nine thousand, one hundred nine".