193649921 has 2 divisors, whose sum is σ = 193649922. Its totient is φ = 193649920.

The previous prime is 193649893. The next prime is 193649933. The reversal of 193649921 is 129946391.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188650225 + 4999696 = 13735^2 + 2236^2 .

It is an emirp because it is prime and its reverse (129946391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 193649921 - 2²⁶ = 126541057 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (193649821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96824960 + 96824961.

It is an arithmetic number, because the mean of its divisors is an integer number (96824961).

Almost surely, 2^193649921 is an apocalyptic number.

It is an amenable number.

193649921 is a deficient number, since it is larger than the sum of its proper divisors (1).

193649921 is an equidigital number, since it uses as much as digits as its factorization.

193649921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 44.

The square root of 193649921 is about 13915.8154989206. The cubic root of 193649921 is about 578.5476156086.

The spelling of 193649921 in words is "one hundred ninety-three million, six hundred forty-nine thousand, nine hundred twenty-one".