100181993 has 4 divisors (see below), whose sum is σ = 100218768. Its totient is φ = 100145220.

The previous prime is 100181989. The next prime is 100181999. The reversal of 100181993 is 399181001.

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: 399181001 = 53 ⋅7531717.

It is a cyclic number.

It is not a de Polignac number, because 100181993 - 2² = 100181989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100181999) 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, 13943 + ... + 19868.

It is an arithmetic number, because the mean of its divisors is an integer number (25054692).

Almost surely, 2^100181993 is an apocalyptic number.

It is an amenable number.

100181993 is a deficient number, since it is larger than the sum of its proper divisors (36775).

100181993 is an equidigital number, since it uses as much as digits as its factorization.

100181993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36774.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 100181993 is about 10009.0955135816. The cubic root of 100181993 is about 464.4402916080.

The spelling of 100181993 in words is "one hundred million, one hundred eighty-one thousand, nine hundred ninety-three".