18922981 has 8 divisors (see below), whose sum is σ = 23592384. Its totient is φ = 14745120.

The previous prime is 18922931. The next prime is 18923039.

18922981 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18922981 - 2¹³ = 18914789 is a prime.

It is a super-2 number, since 2×18922981² = 716158419852722, which 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 (18922901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122800 + ... + 122953.

It is an arithmetic number, because the mean of its divisors is an integer number (2949048).

Almost surely, 2^18922981 is an apocalyptic number.

18922981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18922981 is a deficient number, since it is larger than the sum of its proper divisors (4669403).

18922981 is a wasteful number, since it uses less digits than its factorization.

18922981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245771.

The product of its digits is 20736, while the sum is 40.

The square root of 18922981 is about 4350.0552870050. The cubic root of 18922981 is about 266.4791193437.

The spelling of 18922981 in words is "eighteen million, nine hundred twenty-two thousand, nine hundred eighty-one".