2181304561 has 8 divisors (see below), whose sum is σ = 2322522720. Its totient is φ = 2041520448.

The previous prime is 2181304537. The next prime is 2181304577. The reversal of 2181304561 is 1654031812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2181304561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181304501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355371 + ... + 361456.

It is an arithmetic number, because the mean of its divisors is an integer number (290315340).

Almost surely, 2^2181304561 is an apocalyptic number.

It is an amenable number.

2181304561 is a deficient number, since it is larger than the sum of its proper divisors (141218159).

2181304561 is a wasteful number, since it uses less digits than its factorization.

2181304561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717023.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 2181304561 is about 46704.4383436949. The cubic root of 2181304561 is about 1296.8968512240.

The spelling of 2181304561 in words is "two billion, one hundred eighty-one million, three hundred four thousand, five hundred sixty-one".