18183149981 has 4 divisors (see below), whose sum is σ = 18188894592. Its totient is φ = 18177405372.

The previous prime is 18183149939. The next prime is 18183149993. The reversal of 18183149981 is 18994138181.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18994138181 = 619 ⋅30685199.

It is a cyclic number.

It is not a de Polignac number, because 18183149981 - 2¹⁴ = 18183133597 is a prime.

It is a super-2 number, since 2×18183149981² (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 (18183109981) 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, 2867555 + ... + 2873888.

It is an arithmetic number, because the mean of its divisors is an integer number (4547223648).

Almost surely, 2^18183149981 is an apocalyptic number.

It is an amenable number.

18183149981 is a deficient number, since it is larger than the sum of its proper divisors (5744611).

18183149981 is an equidigital number, since it uses as much as digits as its factorization.

18183149981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5744610.

The product of its digits is 497664, while the sum is 53.

The spelling of 18183149981 in words is "eighteen billion, one hundred eighty-three million, one hundred forty-nine thousand, nine hundred eighty-one".