20211133121 has 4 divisors (see below), whose sum is σ = 20315854212. Its totient is φ = 20106412032.

The previous prime is 20211133099. The next prime is 20211133133. The reversal of 20211133121 is 12133111202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6419214400 + 13791918721 = 80120^2 + 117439^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211133121 - 2⁶ = 20211133057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20211133121.

It is not an unprimeable number, because it can be changed into a prime (20211133181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52360256 + ... + 52360641.

It is an arithmetic number, because the mean of its divisors is an integer number (5078963553).

Almost surely, 2^20211133121 is an apocalyptic number.

It is an amenable number.

20211133121 is a deficient number, since it is larger than the sum of its proper divisors (104721091).

20211133121 is a wasteful number, since it uses less digits than its factorization.

20211133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104721090.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 20211133121 its reverse (12133111202), we get a palindrome (32344244323).

The spelling of 20211133121 in words is "twenty billion, two hundred eleven million, one hundred thirty-three thousand, one hundred twenty-one".