18363636381 has 4 divisors (see below), whose sum is σ = 24484848512. Its totient is φ = 12242424252.

The previous prime is 18363636323. The next prime is 18363636391.

18363636381 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18363636381 - 2¹⁰ = 18363635357 is a prime.

It is a super-2 number, since 2×18363636381² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

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 18363636381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18363636391) 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, 3060606061 + ... + 3060606066.

It is an arithmetic number, because the mean of its divisors is an integer number (6121212128).

Almost surely, 2^18363636381 is an apocalyptic number.

It is an amenable number.

18363636381 is a deficient number, since it is larger than the sum of its proper divisors (6121212131).

18363636381 is an equidigital number, since it uses as much as digits as its factorization.

18363636381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6121212130.

The product of its digits is 1119744, while the sum is 48.

The spelling of 18363636381 in words is "eighteen billion, three hundred sixty-three million, six hundred thirty-six thousand, three hundred eighty-one".