194038993 has 2 divisors, whose sum is σ = 194038994. Its totient is φ = 194038992.

The previous prime is 194038979. The next prime is 194038997. The reversal of 194038993 is 399830491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180956304 + 13082689 = 13452^2 + 3617^2 .

It is a cyclic number.

It is not a de Polignac number, because 194038993 - 2⁵ = 194038961 is a prime.

It is a super-2 number, since 2×194038993² = 75302261608908098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (194038997) 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, 97019496 + 97019497.

It is an arithmetic number, because the mean of its divisors is an integer number (97019497).

Almost surely, 2^194038993 is an apocalyptic number.

It is an amenable number.

194038993 is a deficient number, since it is larger than the sum of its proper divisors (1).

194038993 is an equidigital number, since it uses as much as digits as its factorization.

194038993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 194038993 is about 13929.7879739786. The cubic root of 194038993 is about 578.9348196478.

The spelling of 194038993 in words is "one hundred ninety-four million, thirty-eight thousand, nine hundred ninety-three".