188086993 has 4 divisors (see below), whose sum is σ = 190200420. Its totient is φ = 185973568.

The previous prime is 188086991. The next prime is 188086999. The reversal of 188086993 is 399680881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399680881 = 1259 ⋅317459.

It can be written as a sum of positive squares in 2 ways, for example, as 75047569 + 113039424 = 8663^2 + 10632^2 .

It is a cyclic number.

It is not a de Polignac number, because 188086993 - 2¹ = 188086991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 188086993.

It is not an unprimeable number, because it can be changed into a prime (188086991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1056580 + ... + 1056757.

It is an arithmetic number, because the mean of its divisors is an integer number (47550105).

Almost surely, 2^188086993 is an apocalyptic number.

It is an amenable number.

188086993 is a deficient number, since it is larger than the sum of its proper divisors (2113427).

188086993 is an equidigital number, since it uses as much as digits as its factorization.

188086993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2113426.

The product of its (nonzero) digits is 746496, while the sum is 52.

The square root of 188086993 is about 13714.4811422088. The cubic root of 188086993 is about 572.9537784027.

The spelling of 188086993 in words is "one hundred eighty-eight million, eighty-six thousand, nine hundred ninety-three".