20133131221 has 12 divisors (see below), whose sum is σ = 23991399180. Its totient is φ = 16836066240.

The previous prime is 20133131219. The next prime is 20133131231. The reversal of 20133131221 is 12213133102.

It can be written as a sum of positive squares in 2 ways, for example, as 11462914225 + 8670216996 = 107065^2 + 93114^2 .

It is not a de Polignac number, because 20133131221 - 2¹ = 20133131219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20133131231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5008726 + ... + 5012743.

It is an arithmetic number, because the mean of its divisors is an integer number (1999283265).

Almost surely, 2^20133131221 is an apocalyptic number.

It is an amenable number.

20133131221 is a deficient number, since it is larger than the sum of its proper divisors (3858267959).

20133131221 is a wasteful number, since it uses less digits than its factorization.

20133131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10021524 (or 10021517 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 20133131221 its reverse (12213133102), we get a palindrome (32346264323).

The spelling of 20133131221 in words is "twenty billion, one hundred thirty-three million, one hundred thirty-one thousand, two hundred twenty-one".