99991219 has 4 divisors (see below), whose sum is σ = 100109296. Its totient is φ = 99873144.

The previous prime is 99991207. The next prime is 99991237. The reversal of 99991219 is 91219999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91219999 = 13 ⋅7016923.

It is a cyclic number.

It is not a de Polignac number, because 99991219 - 2¹¹ = 99989171 is a prime.

It is a super-3 number, since 3×99991219³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99991249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57759 + ... + 59464.

It is an arithmetic number, because the mean of its divisors is an integer number (25027324).

Almost surely, 2^99991219 is an apocalyptic number.

99991219 is a deficient number, since it is larger than the sum of its proper divisors (118077).

99991219 is a wasteful number, since it uses less digits than its factorization.

99991219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118076.

The product of its digits is 118098, while the sum is 49.

The square root of 99991219 is about 9999.5609403613. The cubic root of 99991219 is about 464.1452970331.

The spelling of 99991219 in words is "ninety-nine million, nine hundred ninety-one thousand, two hundred nineteen".