194821793 has 2 divisors, whose sum is σ = 194821794. Its totient is φ = 194821792.

The previous prime is 194821789. The next prime is 194821807. The reversal of 194821793 is 397128491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107081104 + 87740689 = 10348^2 + 9367^2 .

It is an emirp because it is prime and its reverse (397128491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194821793 - 2² = 194821789 is a prime.

It is not a weakly prime, because it can be changed into another prime (194821723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97410896 + 97410897.

It is an arithmetic number, because the mean of its divisors is an integer number (97410897).

Almost surely, 2^194821793 is an apocalyptic number.

It is an amenable number.

194821793 is a deficient number, since it is larger than the sum of its proper divisors (1).

194821793 is an equidigital number, since it uses as much as digits as its factorization.

194821793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 194821793 is about 13957.8577511021. The cubic root of 194821793 is about 579.7122958756.

The spelling of 194821793 in words is "one hundred ninety-four million, eight hundred twenty-one thousand, seven hundred ninety-three".