193118921 has 4 divisors (see below), whose sum is σ = 194828052. Its totient is φ = 191409792.

The previous prime is 193118819. The next prime is 193118927. The reversal of 193118921 is 129811391.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129811391 = 6089 ⋅21319.

It can be written as a sum of positive squares in 2 ways, for example, as 29278921 + 163840000 = 5411^2 + 12800^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-193118921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (193118927) 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, 854396 + ... + 854621.

It is an arithmetic number, because the mean of its divisors is an integer number (48707013).

Almost surely, 2^193118921 is an apocalyptic number.

It is an amenable number.

193118921 is a deficient number, since it is larger than the sum of its proper divisors (1709131).

193118921 is a wasteful number, since it uses less digits than its factorization.

193118921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1709130.

The product of its digits is 3888, while the sum is 35.

The square root of 193118921 is about 13896.7233907853. The cubic root of 193118921 is about 578.0183271448.

The spelling of 193118921 in words is "one hundred ninety-three million, one hundred eighteen thousand, nine hundred twenty-one".