190981993 has 2 divisors, whose sum is σ = 190981994. Its totient is φ = 190981992.

The previous prime is 190981981. The next prime is 190982003. The reversal of 190981993 is 399189091.

190981993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 175085824 + 15896169 = 13232^2 + 3987^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-190981993 is a prime.

It is not a weakly prime, because it can be changed into another prime (190981933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95490996 + 95490997.

It is an arithmetic number, because the mean of its divisors is an integer number (95490997).

Almost surely, 2^190981993 is an apocalyptic number.

It is an amenable number.

190981993 is a deficient number, since it is larger than the sum of its proper divisors (1).

190981993 is an equidigital number, since it uses as much as digits as its factorization.

190981993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 157464, while the sum is 49.

The square root of 190981993 is about 13819.6234753339. The cubic root of 190981993 is about 575.8784234549.

The spelling of 190981993 in words is "one hundred ninety million, nine hundred eighty-one thousand, nine hundred ninety-three".