18661382319 has 4 divisors (see below), whose sum is σ = 24881843096. Its totient is φ = 12440921544.

The previous prime is 18661382297. The next prime is 18661382357. The reversal of 18661382319 is 91328316681.

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

It is not a de Polignac number, because 18661382319 - 2⁵ = 18661382287 is a prime.

It is a super-2 number, since 2×18661382319² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18661382359) 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, 3110230384 + ... + 3110230389.

It is an arithmetic number, because the mean of its divisors is an integer number (6220460774).

Almost surely, 2^18661382319 is an apocalyptic number.

18661382319 is a deficient number, since it is larger than the sum of its proper divisors (6220460777).

18661382319 is an equidigital number, since it uses as much as digits as its factorization.

18661382319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6220460776.

The product of its digits is 373248, while the sum is 48.

The spelling of 18661382319 in words is "eighteen billion, six hundred sixty-one million, three hundred eighty-two thousand, three hundred nineteen".