2181665467 has 4 divisors (see below), whose sum is σ = 2184323616. Its totient is φ = 2179007320.

The previous prime is 2181665449. The next prime is 2181665503. The reversal of 2181665467 is 7645661812.

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 2181665467 - 2²⁷ = 2047447739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181665567) 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 3 ways as a sum of consecutive naturals, for example, 1327843 + ... + 1329484.

It is an arithmetic number, because the mean of its divisors is an integer number (546080904).

Almost surely, 2^2181665467 is an apocalyptic number.

2181665467 is a deficient number, since it is larger than the sum of its proper divisors (2658149).

2181665467 is an equidigital number, since it uses as much as digits as its factorization.

2181665467 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2658148.

The product of its digits is 483840, while the sum is 46.

The square root of 2181665467 is about 46708.3019066204. The cubic root of 2181665467 is about 1296.9683729564.

The spelling of 2181665467 in words is "two billion, one hundred eighty-one million, six hundred sixty-five thousand, four hundred sixty-seven".