2121340021 has 8 divisors (see below), whose sum is σ = 2137695840. Its totient is φ = 2105000112.

The previous prime is 2121339991. The next prime is 2121340031. The reversal of 2121340021 is 1200431212.

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-2121340021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121339977 and 2121340004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121340031) 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, 526611 + ... + 530623.

It is an arithmetic number, because the mean of its divisors is an integer number (267211980).

Almost surely, 2^2121340021 is an apocalyptic number.

It is an amenable number.

2121340021 is a deficient number, since it is larger than the sum of its proper divisors (16355819).

2121340021 is a wasteful number, since it uses less digits than its factorization.

2121340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7955.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2121340021 is about 46058.0071323109. The cubic root of 2121340021 is about 1284.9022663333.

Adding to 2121340021 its reverse (1200431212), we get a palindrome (3321771233).

The spelling of 2121340021 in words is "two billion, one hundred twenty-one million, three hundred forty thousand, twenty-one".