188211987 has 12 divisors (see below), whose sum is σ = 273664144. Its totient is φ = 124642800.

The previous prime is 188211953. The next prime is 188212019. The reversal of 188211987 is 789112881.

It is a happy number.

It is not a de Polignac number, because 188211987 - 2¹⁶ = 188146451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (188211917) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67888 + ... + 70605.

Almost surely, 2^188211987 is an apocalyptic number.

188211987 is a deficient number, since it is larger than the sum of its proper divisors (85452157).

188211987 is a wasteful number, since it uses less digits than its factorization.

188211987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138650 (or 138647 counting only the distinct ones).

The product of its digits is 64512, while the sum is 45.

The square root of 188211987 is about 13719.0373933451. The cubic root of 188211987 is about 573.0806699102.

The spelling of 188211987 in words is "one hundred eighty-eight million, two hundred eleven thousand, nine hundred eighty-seven".