189943381 has 2 divisors, whose sum is σ = 189943382. Its totient is φ = 189943380.

The previous prime is 189943343. The next prime is 189943393. The reversal of 189943381 is 183349981.

It is a happy number.

189943381 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., 154778481 + 35164900 = 12441^2 + 5930^2 .

It is a cyclic number.

It is not a de Polignac number, because 189943381 - 2⁷ = 189943253 is a prime.

It is a super-2 number, since 2×189943381² = 72156975971422322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189943331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94971690 + 94971691.

It is an arithmetic number, because the mean of its divisors is an integer number (94971691).

Almost surely, 2^189943381 is an apocalyptic number.

It is an amenable number.

189943381 is a deficient number, since it is larger than the sum of its proper divisors (1).

189943381 is an equidigital number, since it uses as much as digits as its factorization.

189943381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 46.

The square root of 189943381 is about 13781.9948120727. The cubic root of 189943381 is about 574.8325975188.

The spelling of 189943381 in words is "one hundred eighty-nine million, nine hundred forty-three thousand, three hundred eighty-one".