2191923979 has 8 divisors (see below), whose sum is σ = 2505514208. Its totient is φ = 1878448320.

The previous prime is 2191923977. The next prime is 2191924027. The reversal of 2191923979 is 9793291912.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2191923979 - 2¹ = 2191923977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2191923973) 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 in 7 ways as a sum of consecutive naturals, for example, 17269 + ... + 68425.

It is an arithmetic number, because the mean of its divisors is an integer number (313189276).

Almost surely, 2^2191923979 is an apocalyptic number.

2191923979 is a deficient number, since it is larger than the sum of its proper divisors (313590229).

2191923979 is an equidigital number, since it uses as much as digits as its factorization.

2191923979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57285.

The product of its digits is 551124, while the sum is 52.

The square root of 2191923979 is about 46817.9877717956. The cubic root of 2191923979 is about 1298.9980403759.

The spelling of 2191923979 in words is "two billion, one hundred ninety-one million, nine hundred twenty-three thousand, nine hundred seventy-nine".