193978409 has 2 divisors, whose sum is σ = 193978410. Its totient is φ = 193978408.

The previous prime is 193978397. The next prime is 193978423. The reversal of 193978409 is 904879391.

193978409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126787600 + 67190809 = 11260^2 + 8197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-193978409 is a prime.

It is not a weakly prime, because it can be changed into another prime (193978459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96989204 + 96989205.

It is an arithmetic number, because the mean of its divisors is an integer number (96989205).

Almost surely, 2^193978409 is an apocalyptic number.

It is an amenable number.

193978409 is a deficient number, since it is larger than the sum of its proper divisors (1).

193978409 is an equidigital number, since it uses as much as digits as its factorization.

193978409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 193978409 is about 13927.6131838876. The cubic root of 193978409 is about 578.8745605601.

The spelling of 193978409 in words is "one hundred ninety-three million, nine hundred seventy-eight thousand, four hundred nine".