188139569 has 2 divisors, whose sum is σ = 188139570. Its totient is φ = 188139568.

The previous prime is 188139557. The next prime is 188139571. The reversal of 188139569 is 965931881.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129049600 + 59089969 = 11360^2 + 7687^2 .

It is an emirp because it is prime and its reverse (965931881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188139569 is a prime.

It is a super-2 number, since 2×188139569² = 70792994847011522, which contains 22 as substring.

Together with 188139571, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (188139599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94069784 + 94069785.

It is an arithmetic number, because the mean of its divisors is an integer number (94069785).

Almost surely, 2^188139569 is an apocalyptic number.

It is an amenable number.

188139569 is a deficient number, since it is larger than the sum of its proper divisors (1).

188139569 is an equidigital number, since it uses as much as digits as its factorization.

188139569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 50.

The square root of 188139569 is about 13716.3978142951. The cubic root of 188139569 is about 573.0071593959.

It can be divided in two parts, 18813 and 9569, that added together give a palindrome (28382).

The spelling of 188139569 in words is "one hundred eighty-eight million, one hundred thirty-nine thousand, five hundred sixty-nine".