199548521 has 2 divisors, whose sum is σ = 199548522. Its totient is φ = 199548520.

The previous prime is 199548491. The next prime is 199548523. The reversal of 199548521 is 125845991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178489600 + 21058921 = 13360^2 + 4589^2 .

It is a cyclic number.

It is not a de Polignac number, because 199548521 - 2¹⁸ = 199286377 is a prime.

It is a super-2 number, since 2×199548521² = 79639224466574882, which contains 22 as substring.

Together with 199548523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199548523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99774260 + 99774261.

It is an arithmetic number, because the mean of its divisors is an integer number (99774261).

Almost surely, 2^199548521 is an apocalyptic number.

It is an amenable number.

199548521 is a deficient number, since it is larger than the sum of its proper divisors (1).

199548521 is an equidigital number, since it uses as much as digits as its factorization.

199548521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 44.

The square root of 199548521 is about 14126.1644121821. The cubic root of 199548521 is about 584.3631719074.

The spelling of 199548521 in words is "one hundred ninety-nine million, five hundred forty-eight thousand, five hundred twenty-one".