188485991 has 2 divisors, whose sum is σ = 188485992. Its totient is φ = 188485990.

The previous prime is 188485951. The next prime is 188486017. The reversal of 188485991 is 199584881.

It is a happy number.

188485991 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 is an emirp because it is prime and its reverse (199584881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188485991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188485951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94242995 + 94242996.

It is an arithmetic number, because the mean of its divisors is an integer number (94242996).

Almost surely, 2^188485991 is an apocalyptic number.

188485991 is a deficient number, since it is larger than the sum of its proper divisors (1).

188485991 is an equidigital number, since it uses as much as digits as its factorization.

188485991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 53.

The square root of 188485991 is about 13729.0200305776. The cubic root of 188485991 is about 573.3586370735.

The spelling of 188485991 in words is "one hundred eighty-eight million, four hundred eighty-five thousand, nine hundred ninety-one".