18426520709 has 4 divisors (see below), whose sum is σ = 18428155116. Its totient is φ = 18424886304.

The previous prime is 18426520703. The next prime is 18426520729. The reversal of 18426520709 is 90702562481.

It is a happy number.

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 3456264100 + 14970256609 = 58790^2 + 122353^2 .

It is a cyclic number.

It is not a de Polignac number, because 18426520709 - 2³² = 14131553413 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18426520709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18426520703) 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, 800174 + ... + 822879.

It is an arithmetic number, because the mean of its divisors is an integer number (4607038779).

Almost surely, 2^18426520709 is an apocalyptic number.

It is an amenable number.

18426520709 is a deficient number, since it is larger than the sum of its proper divisors (1634407).

18426520709 is a wasteful number, since it uses less digits than its factorization.

18426520709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1634406.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 18426520709 in words is "eighteen billion, four hundred twenty-six million, five hundred twenty thousand, seven hundred nine".