18385658381 has 4 divisors (see below), whose sum is σ = 18557487072. Its totient is φ = 18213829692.

The previous prime is 18385658371. The next prime is 18385658441.

It is a happy number.

18385658381 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 a cyclic number.

It is not a de Polignac number, because 18385658381 - 2²² = 18381464077 is a prime.

It is a super-2 number, since 2×18385658381² (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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (18385658371) 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, 85914185 + ... + 85914398.

It is an arithmetic number, because the mean of its divisors is an integer number (4639371768).

Almost surely, 2^18385658381 is an apocalyptic number.

It is an amenable number.

18385658381 is a deficient number, since it is larger than the sum of its proper divisors (171828691).

18385658381 is a wasteful number, since it uses less digits than its factorization.

18385658381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171828690.

The product of its digits is 5529600, while the sum is 56.

The spelling of 18385658381 in words is "eighteen billion, three hundred eighty-five million, six hundred fifty-eight thousand, three hundred eighty-one".