18303513649 has 4 divisors (see below), whose sum is σ = 18492209764. Its totient is φ = 18114817536.

The previous prime is 18303513617. The next prime is 18303513703. The reversal of 18303513649 is 94631530381.

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 10919205025 + 7384308624 = 104495^2 + 85932^2 .

It is a cyclic number.

It is not a de Polignac number, because 18303513649 - 2⁵ = 18303513617 is a prime.

It is a super-4 number, since 4×18303513649⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18303513049) 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, 94347912 + ... + 94348105.

It is an arithmetic number, because the mean of its divisors is an integer number (4623052441).

Almost surely, 2^18303513649 is an apocalyptic number.

It is an amenable number.

18303513649 is a deficient number, since it is larger than the sum of its proper divisors (188696115).

18303513649 is an equidigital number, since it uses as much as digits as its factorization.

18303513649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188696114.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 18303513649 in words is "eighteen billion, three hundred three million, five hundred thirteen thousand, six hundred forty-nine".