189089981 has 2 divisors, whose sum is σ = 189089982. Its totient is φ = 189089980.

The previous prime is 189089959. The next prime is 189089993. The reversal of 189089981 is 189980981.

189089981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110040100 + 79049881 = 10490^2 + 8891^2 .

It is a cyclic number.

It is not a de Polignac number, because 189089981 - 2⁶ = 189089917 is a prime.

It is a super-2 number, since 2×189089981² = 71510041829160722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189089921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94544990 + 94544991.

It is an arithmetic number, because the mean of its divisors is an integer number (94544991).

Almost surely, 2^189089981 is an apocalyptic number.

It is an amenable number.

189089981 is a deficient number, since it is larger than the sum of its proper divisors (1).

189089981 is an equidigital number, since it uses as much as digits as its factorization.

189089981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 53.

The square root of 189089981 is about 13750.9992727801. Note that the first 3 decimals coincide. The cubic root of 189089981 is about 573.9704131132.

The spelling of 189089981 in words is "one hundred eighty-nine million, eighty-nine thousand, nine hundred eighty-one".