188885891 has 2 divisors, whose sum is σ = 188885892. Its totient is φ = 188885890.

The previous prime is 188885881. The next prime is 188885899. The reversal of 188885891 is 198588881.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 188885891 - 2¹⁰ = 188884867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (188885899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94442945 + 94442946.

It is an arithmetic number, because the mean of its divisors is an integer number (94442946).

Almost surely, 2^188885891 is an apocalyptic number.

188885891 is a deficient number, since it is larger than the sum of its proper divisors (1).

188885891 is an equidigital number, since it uses as much as digits as its factorization.

188885891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1474560, while the sum is 56.

The square root of 188885891 is about 13743.5763540645. The cubic root of 188885891 is about 573.7638381076.

The spelling of 188885891 in words is "one hundred eighty-eight million, eight hundred eighty-five thousand, eight hundred ninety-one".