2191916213 has 4 divisors (see below), whose sum is σ = 2192195148. Its totient is φ = 2191637280.

The previous prime is 2191916179. The next prime is 2191916219. The reversal of 2191916213 is 3126191912.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1752510769 + 439405444 = 41863^2 + 20962^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191916213 - 2¹⁰ = 2191915189 is a prime.

It is a super-2 number, since 2×2191916213² = 9608993369624522738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191916219) 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 in 3 ways as a sum of consecutive naturals, for example, 127328 + ... + 143513.

It is an arithmetic number, because the mean of its divisors is an integer number (548048787).

Almost surely, 2^2191916213 is an apocalyptic number.

It is an amenable number.

2191916213 is a deficient number, since it is larger than the sum of its proper divisors (278935).

2191916213 is an equidigital number, since it uses as much as digits as its factorization.

2191916213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278934.

The product of its digits is 5832, while the sum is 35.

The square root of 2191916213 is about 46817.9048335143. The cubic root of 2191916213 is about 1298.9965062548.

The spelling of 2191916213 in words is "two billion, one hundred ninety-one million, nine hundred sixteen thousand, two hundred thirteen".