21131031232221 has 8 divisors (see below), whose sum is σ = 28181078372160. Its totient is φ = 14084169123552.

The previous prime is 21131031232081. The next prime is 21131031232261. The reversal of 21131031232221 is 12223213013112.

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

It is not a de Polignac number, because 21131031232221 - 2¹⁰ = 21131031231197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131031232191 and 21131031232200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131031232261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 796242336 + ... + 796268873.

It is an arithmetic number, because the mean of its divisors is an integer number (3522634796520).

Almost surely, 2^{21131031232221} is an apocalyptic number.

It is an amenable number.

21131031232221 is a deficient number, since it is larger than the sum of its proper divisors (7050047139939).

21131031232221 is a wasteful number, since it uses less digits than its factorization.

21131031232221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1592515635.

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 21131031232221 its reverse (12223213013112), we get a palindrome (33354244245333).

The spelling of 21131031232221 in words is "twenty-one trillion, one hundred thirty-one billion, thirty-one million, two hundred thirty-two thousand, two hundred twenty-one".