2121607561 has 8 divisors (see below), whose sum is σ = 2215195200. Its totient is φ = 2028131952.

The previous prime is 2121607559. The next prime is 2121607577. The reversal of 2121607561 is 1657061212.

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

It is a cyclic number.

It is not a de Polignac number, because 2121607561 - 2¹ = 2121607559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121601561) 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 7 ways as a sum of consecutive naturals, for example, 11931 + ... + 66223.

It is an arithmetic number, because the mean of its divisors is an integer number (276899400).

Almost surely, 2^2121607561 is an apocalyptic number.

It is an amenable number.

2121607561 is a deficient number, since it is larger than the sum of its proper divisors (93587639).

2121607561 is a wasteful number, since it uses less digits than its factorization.

2121607561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56015.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 2121607561 is about 46060.9114217250. The cubic root of 2121607561 is about 1284.9562806667.

Adding to 2121607561 its reverse (1657061212), we get a palindrome (3778668773).

The spelling of 2121607561 in words is "two billion, one hundred twenty-one million, six hundred seven thousand, five hundred sixty-one".