2167921491 has 4 divisors (see below), whose sum is σ = 2890561992. Its totient is φ = 1445280992.

The previous prime is 2167921421. The next prime is 2167921493. The reversal of 2167921491 is 1941297612.

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 2167921491 - 2²² = 2163727187 is a prime.

It is a super-2 number, since 2×2167921491² = 9399767182279326162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2167921493) 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, 361320246 + ... + 361320251.

It is an arithmetic number, because the mean of its divisors is an integer number (722640498).

Almost surely, 2^2167921491 is an apocalyptic number.

2167921491 is a deficient number, since it is larger than the sum of its proper divisors (722640501).

2167921491 is an equidigital number, since it uses as much as digits as its factorization.

2167921491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722640500.

The product of its digits is 54432, while the sum is 42.

The square root of 2167921491 is about 46560.9438370830. The cubic root of 2167921491 is about 1294.2391024107.

The spelling of 2167921491 in words is "two billion, one hundred sixty-seven million, nine hundred twenty-one thousand, four hundred ninety-one".