20991199219 has 4 divisors (see below), whose sum is σ = 21227055480. Its totient is φ = 20755342960.

The previous prime is 20991199171. The next prime is 20991199231. The reversal of 20991199219 is 91299119902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20991199219 - 2²¹ = 20989102067 is a prime.

It is a super-2 number, since 2×20991199219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20991199249) 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, 117927997 + ... + 117928174.

It is an arithmetic number, because the mean of its divisors is an integer number (5306763870).

Almost surely, 2^20991199219 is an apocalyptic number.

20991199219 is a deficient number, since it is larger than the sum of its proper divisors (235856261).

20991199219 is an equidigital number, since it uses as much as digits as its factorization.

20991199219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235856260.

The product of its (nonzero) digits is 236196, while the sum is 52.

The spelling of 20991199219 in words is "twenty billion, nine hundred ninety-one million, one hundred ninety-nine thousand, two hundred nineteen".