20211012221 has 4 divisors (see below), whose sum is σ = 20226596412. Its totient is φ = 20195428032.

The previous prime is 20211012191. The next prime is 20211012259. The reversal of 20211012221 is 12221011202.

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 10033027225 + 10177984996 = 100165^2 + 100886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211012221 is a prime.

It is a super-2 number, since 2×20211012221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211012196 and 20211012205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211012271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7790150 + ... + 7792743.

It is an arithmetic number, because the mean of its divisors is an integer number (5056649103).

Almost surely, 2^20211012221 is an apocalyptic number.

It is an amenable number.

20211012221 is a deficient number, since it is larger than the sum of its proper divisors (15584191).

20211012221 is a wasteful number, since it uses less digits than its factorization.

20211012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15584190.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20211012221 its reverse (12221011202), we get a palindrome (32432023423).

The spelling of 20211012221 in words is "twenty billion, two hundred eleven million, twelve thousand, two hundred twenty-one".