199717457 has 2 divisors, whose sum is σ = 199717458. Its totient is φ = 199717456.

The previous prime is 199717439. The next prime is 199717549. The reversal of 199717457 is 754717991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147646801 + 52070656 = 12151^2 + 7216^2 .

It is an emirp because it is prime and its reverse (754717991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199717457 - 2¹² = 199713361 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199717057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99858728 + 99858729.

It is an arithmetic number, because the mean of its divisors is an integer number (99858729).

Almost surely, 2^199717457 is an apocalyptic number.

It is an amenable number.

199717457 is a deficient number, since it is larger than the sum of its proper divisors (1).

199717457 is an equidigital number, since it uses as much as digits as its factorization.

199717457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 555660, while the sum is 50.

The square root of 199717457 is about 14132.1426896278. The cubic root of 199717457 is about 584.5280309450.

The spelling of 199717457 in words is "one hundred ninety-nine million, seven hundred seventeen thousand, four hundred fifty-seven".