18189943958 has 4 divisors (see below), whose sum is σ = 27284915940. Its totient is φ = 9094971978.

The previous prime is 18189943931. The next prime is 18189943969. The reversal of 18189943958 is 85934998181.

It is a happy number.

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

It is a super-2 number, since 2×18189943958² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18189943894 and 18189943903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4547485988 + ... + 4547485991.

It is an arithmetic number, because the mean of its divisors is an integer number (6821228985).

Almost surely, 2^18189943958 is an apocalyptic number.

18189943958 is a deficient number, since it is larger than the sum of its proper divisors (9094971982).

18189943958 is an equidigital number, since it uses as much as digits as its factorization.

18189943958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9094971981.

The product of its digits is 22394880, while the sum is 65.

The spelling of 18189943958 in words is "eighteen billion, one hundred eighty-nine million, nine hundred forty-three thousand, nine hundred fifty-eight".