188639889 has 4 divisors (see below), whose sum is σ = 251519856. Its totient is φ = 125759924.

The previous prime is 188639887. The next prime is 188639897. The reversal of 188639889 is 988936881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 988936881 = 3 ⋅329645627.

It is a cyclic number.

It is not a de Polignac number, because 188639889 - 2¹ = 188639887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (188639887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31439979 + ... + 31439984.

It is an arithmetic number, because the mean of its divisors is an integer number (62879964).

Almost surely, 2^188639889 is an apocalyptic number.

It is an amenable number.

188639889 is a deficient number, since it is larger than the sum of its proper divisors (62879967).

188639889 is an equidigital number, since it uses as much as digits as its factorization.

188639889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62879966.

The product of its digits is 5971968, while the sum is 60.

The square root of 188639889 is about 13734.6237298297. The cubic root of 188639889 is about 573.5146429079.

The spelling of 188639889 in words is "one hundred eighty-eight million, six hundred thirty-nine thousand, eight hundred eighty-nine".