18994339181 has 4 divisors (see below), whose sum is σ = 19078014912. Its totient is φ = 18910663452.

The previous prime is 18994339157. The next prime is 18994339249. The reversal of 18994339181 is 18193349981.

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: 18193349981 = 61673 ⋅294997.

It is a cyclic number.

It is not a de Polignac number, because 18994339181 - 2³⁴ = 1814469997 is a prime.

It is a super-2 number, since 2×18994339181² (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 (18994339141) 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, 41837525 + ... + 41837978.

It is an arithmetic number, because the mean of its divisors is an integer number (4769503728).

Almost surely, 2^18994339181 is an apocalyptic number.

It is an amenable number.

18994339181 is a deficient number, since it is larger than the sum of its proper divisors (83675731).

18994339181 is an equidigital number, since it uses as much as digits as its factorization.

18994339181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83675730.

The product of its digits is 1679616, while the sum is 56.

The spelling of 18994339181 in words is "eighteen billion, nine hundred ninety-four million, three hundred thirty-nine thousand, one hundred eighty-one".