1999445197 has 2 divisors, whose sum is σ = 1999445198. Its totient is φ = 1999445196.

The previous prime is 1999445179. The next prime is 1999445233. The reversal of 1999445197 is 7915449991.

Together with previous prime (1999445179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1176558601 + 822886596 = 34301^2 + 28686^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999445197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999445797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999722598 + 999722599.

It is an arithmetic number, because the mean of its divisors is an integer number (999722599).

Almost surely, 2^1999445197 is an apocalyptic number.

It is an amenable number.

1999445197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999445197 is an equidigital number, since it uses as much as digits as its factorization.

1999445197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3674160, while the sum is 58.

The square root of 1999445197 is about 44715.1562336530. The cubic root of 1999445197 is about 1259.8045377910.

The spelling of 1999445197 in words is "one billion, nine hundred ninety-nine million, four hundred forty-five thousand, one hundred ninety-seven".