199389121 has 2 divisors, whose sum is σ = 199389122. Its totient is φ = 199389120.

The previous prime is 199389101. The next prime is 199389161. The reversal of 199389121 is 121983991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198810000 + 579121 = 14100^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 199389121 - 2¹⁹ = 198864833 is a prime.

It is not a weakly prime, because it can be changed into another prime (199389101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99694560 + 99694561.

It is an arithmetic number, because the mean of its divisors is an integer number (99694561).

Almost surely, 2^199389121 is an apocalyptic number.

It is an amenable number.

199389121 is a deficient number, since it is larger than the sum of its proper divisors (1).

199389121 is an equidigital number, since it uses as much as digits as its factorization.

199389121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 43.

The square root of 199389121 is about 14120.5212722477. The cubic root of 199389121 is about 584.2075333985.

The spelling of 199389121 in words is "one hundred ninety-nine million, three hundred eighty-nine thousand, one hundred twenty-one".