2181346809 has 4 divisors (see below), whose sum is σ = 2908462416. Its totient is φ = 1454231204.

The previous prime is 2181346807. The next prime is 2181346859. The reversal of 2181346809 is 9086431812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2181346809 - 2¹ = 2181346807 is a prime.

It is a super-2 number, since 2×2181346809² = 9516547802268964962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2181346801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363557799 + ... + 363557804.

It is an arithmetic number, because the mean of its divisors is an integer number (727115604).

Almost surely, 2^2181346809 is an apocalyptic number.

It is an amenable number.

2181346809 is a deficient number, since it is larger than the sum of its proper divisors (727115607).

2181346809 is an equidigital number, since it uses as much as digits as its factorization.

2181346809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727115606.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 2181346809 is about 46704.8906325665. The cubic root of 2181346809 is about 1296.9052240338.

The spelling of 2181346809 in words is "two billion, one hundred eighty-one million, three hundred forty-six thousand, eight hundred nine".