2121023131221 has 16 divisors (see below), whose sum is σ = 2844456917120. Its totient is φ = 1405806788160.

The previous prime is 2121023131091. The next prime is 2121023131237. The reversal of 2121023131221 is 1221313201212.

It is not a de Polignac number, because 2121023131221 - 2¹⁹ = 2121022606933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121023131321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1383771 + ... + 2481303.

It is an arithmetic number, because the mean of its divisors is an integer number (177778557320).

Almost surely, 2^{2121023131221} is an apocalyptic number.

It is an amenable number.

2121023131221 is a deficient number, since it is larger than the sum of its proper divisors (723433785899).

2121023131221 is a wasteful number, since it uses less digits than its factorization.

2121023131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101276.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 2121023131221 its reverse (1221313201212), we get a palindrome (3342336332433).

The spelling of 2121023131221 in words is "two trillion, one hundred twenty-one billion, twenty-three million, one hundred thirty-one thousand, two hundred twenty-one".