20211231133221 has 8 divisors (see below), whose sum is σ = 28533502776384. Its totient is φ = 12681556789440.

The previous prime is 20211231133183. The next prime is 20211231133243. The reversal of 20211231133221 is 12233113211202.

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

It is not a de Polignac number, because 20211231133221 - 2²¹ = 20211229036069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211231133191 and 20211231133200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211231133021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198149324785 + ... + 198149324886.

It is an arithmetic number, because the mean of its divisors is an integer number (3566687847048).

Almost surely, 2^{20211231133221} is an apocalyptic number.

It is an amenable number.

20211231133221 is a deficient number, since it is larger than the sum of its proper divisors (8322271643163).

20211231133221 is a wasteful number, since it uses less digits than its factorization.

20211231133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396298649691.

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

Adding to 20211231133221 its reverse (12233113211202), we get a palindrome (32444344344423).

The spelling of 20211231133221 in words is "twenty trillion, two hundred eleven billion, two hundred thirty-one million, one hundred thirty-three thousand, two hundred twenty-one".