18954445981 has 4 divisors (see below), whose sum is σ = 19778552352. Its totient is φ = 18130339612.

The previous prime is 18954445969. The next prime is 18954445997.

18954445981 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 18954445981 - 2¹⁵ = 18954413213 is a prime.

It is a super-2 number, since 2×18954445981² (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 (18954445921) 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, 412053151 + ... + 412053196.

It is an arithmetic number, because the mean of its divisors is an integer number (4944638088).

Almost surely, 2^18954445981 is an apocalyptic number.

It is an amenable number.

18954445981 is a deficient number, since it is larger than the sum of its proper divisors (824106371).

18954445981 is an equidigital number, since it uses as much as digits as its factorization.

18954445981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824106370.

The product of its digits is 8294400, while the sum is 58.

The spelling of 18954445981 in words is "eighteen billion, nine hundred fifty-four million, four hundred forty-five thousand, nine hundred eighty-one".