188889889 has 2 divisors, whose sum is σ = 188889890. Its totient is φ = 188889888.

The previous prime is 188889871. The next prime is 188889919. The reversal of 188889889 is 988988881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174028864 + 14861025 = 13192^2 + 3855^2 .

It is a cyclic number.

It is not a de Polignac number, because 188889889 - 2⁷ = 188889761 is a prime.

It is not a weakly prime, because it can be changed into another prime (188889689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94444944 + 94444945.

It is an arithmetic number, because the mean of its divisors is an integer number (94444945).

Almost surely, 2^188889889 is an apocalyptic number.

It is an amenable number.

188889889 is a deficient number, since it is larger than the sum of its proper divisors (1).

188889889 is an equidigital number, since it uses as much as digits as its factorization.

188889889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21233664, while the sum is 67.

The square root of 188889889 is about 13743.7218030634. The cubic root of 188889889 is about 573.7678862159.

The spelling of 188889889 in words is "one hundred eighty-eight million, eight hundred eighty-nine thousand, eight hundred eighty-nine".