2121334644521 has 4 divisors (see below), whose sum is σ = 2121337561344. Its totient is φ = 2121331727700.

The previous prime is 2121334644509. The next prime is 2121334644551. The reversal of 2121334644521 is 1254464331212.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2121334644521 - 2¹⁴ = 2121334628137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121334644551) 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, 616676 + ... + 2150106.

It is an arithmetic number, because the mean of its divisors is an integer number (530334390336).

Almost surely, 2^{2121334644521} is an apocalyptic number.

It is an amenable number.

2121334644521 is a deficient number, since it is larger than the sum of its proper divisors (2916823).

2121334644521 is a wasteful number, since it uses less digits than its factorization.

2121334644521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2916822.

The product of its digits is 138240, while the sum is 38.

Adding to 2121334644521 its reverse (1254464331212), we get a palindrome (3375798975733).

The spelling of 2121334644521 in words is "two trillion, one hundred twenty-one billion, three hundred thirty-four million, six hundred forty-four thousand, five hundred twenty-one".