2021131312221 has 32 divisors (see below), whose sum is σ = 3148417843200. Its totient is φ = 1129412646720.

The previous prime is 2021131312093. The next prime is 2021131312223. The reversal of 2021131312221 is 1222131311202.

It is not a de Polignac number, because 2021131312221 - 2⁷ = 2021131312093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021131312223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4033666 + ... + 4506963.

It is an arithmetic number, because the mean of its divisors is an integer number (98388057600).

Almost surely, 2^{2021131312221} is an apocalyptic number.

2021131312221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2021131312221 is a deficient number, since it is larger than the sum of its proper divisors (1127286530979).

2021131312221 is a wasteful number, since it uses less digits than its factorization.

2021131312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8540889.

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

Adding to 2021131312221 its reverse (1222131311202), we get a palindrome (3243262623423).

The spelling of 2021131312221 in words is "two trillion, twenty-one billion, one hundred thirty-one million, three hundred twelve thousand, two hundred twenty-one".