189929981 has 2 divisors, whose sum is σ = 189929982. Its totient is φ = 189929980.

The previous prime is 189929969. The next prime is 189930007.

189929981 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., 172003225 + 17926756 = 13115^2 + 4234^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 189929981 - 2¹⁰ = 189928957 is a prime.

It is a super-2 number, since 2×189929981² = 72146795365320722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189929911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94964990 + 94964991.

It is an arithmetic number, because the mean of its divisors is an integer number (94964991).

Almost surely, 2^189929981 is an apocalyptic number.

It is an amenable number.

189929981 is a deficient number, since it is larger than the sum of its proper divisors (1).

189929981 is an equidigital number, since it uses as much as digits as its factorization.

189929981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 56.

The square root of 189929981 is about 13781.5086619717. The cubic root of 189929981 is about 574.8190795643.

The spelling of 189929981 in words is "one hundred eighty-nine million, nine hundred twenty-nine thousand, nine hundred eighty-one".