199016581 has 2 divisors, whose sum is σ = 199016582. Its totient is φ = 199016580.

The previous prime is 199016579. The next prime is 199016593. The reversal of 199016581 is 185610991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131102500 + 67914081 = 11450^2 + 8241^2 .

It is a cyclic number.

It is not a de Polignac number, because 199016581 - 2¹ = 199016579 is a prime.

It is a super-2 number, since 2×199016581² = 79215199025859122, which contains 22 as substring.

Together with 199016579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199016551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99508290 + 99508291.

It is an arithmetic number, because the mean of its divisors is an integer number (99508291).

Almost surely, 2^199016581 is an apocalyptic number.

It is an amenable number.

199016581 is a deficient number, since it is larger than the sum of its proper divisors (1).

199016581 is an equidigital number, since it uses as much as digits as its factorization.

199016581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 40.

The square root of 199016581 is about 14107.3236653874. The cubic root of 199016581 is about 583.8434607727.

The spelling of 199016581 in words is "one hundred ninety-nine million, sixteen thousand, five hundred eighty-one".