221020211020021 has 12 divisors (see below), whose sum is σ = 257117448070188. Its totient is φ = 189436828584192.

The previous prime is 221020211019983. The next prime is 221020211020031. The reversal of 221020211020021 is 120020112020122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 85015517988996 + 136004693031025 = 9220386^2 + 11662105^2 .

It is not a de Polignac number, because 221020211020021 - 2¹³ = 221020211011829 is a prime.

It is a super-2 number, since 2×221020211020021² (a number of 29 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 = 221020211019977 and 221020211020004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020211020031) 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 11 ways as a sum of consecutive naturals, for example, 106901026 + ... + 108948931.

It is an arithmetic number, because the mean of its divisors is an integer number (21426454005849).

Almost surely, 2^{221020211020021} is an apocalyptic number.

It is an amenable number.

221020211020021 is a deficient number, since it is larger than the sum of its proper divisors (36097237050167).

221020211020021 is a wasteful number, since it uses less digits than its factorization.

221020211020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215870868 (or 215870861 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221020211020021 its reverse (120020112020122), we get a palindrome (341040323040143).

The spelling of 221020211020021 in words is "two hundred twenty-one trillion, twenty billion, two hundred eleven million, twenty thousand, twenty-one".