189838981 has 2 divisors, whose sum is σ = 189838982. Its totient is φ = 189838980.

The previous prime is 189838973. The next prime is 189838997.

189838981 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178649956 + 11189025 = 13366^2 + 3345^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 189838981 - 2³ = 189838973 is a prime.

It is a super-2 number, since 2×189838981² = 72077677414236722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189838921) 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 as a sum of consecutive naturals, namely, 94919490 + 94919491.

It is an arithmetic number, because the mean of its divisors is an integer number (94919491).

Almost surely, 2^189838981 is an apocalyptic number.

It is an amenable number.

189838981 is a deficient number, since it is larger than the sum of its proper divisors (1).

189838981 is an equidigital number, since it uses as much as digits as its factorization.

189838981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 55.

The square root of 189838981 is about 13778.2067410821. The cubic root of 189838981 is about 574.7272617055.

The spelling of 189838981 in words is "one hundred eighty-nine million, eight hundred thirty-eight thousand, nine hundred eighty-one".