20212101221 has 4 divisors (see below), whose sum is σ = 21766878252. Its totient is φ = 18657324192.

The previous prime is 20212101211. The next prime is 20212101307. The reversal of 20212101221 is 12210121202.

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 3412312225 + 16799788996 = 58415^2 + 129614^2 .

It is not a de Polignac number, because 20212101221 - 2¹⁰ = 20212100197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20212101196 and 20212101205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212101211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777388496 + ... + 777388521.

It is an arithmetic number, because the mean of its divisors is an integer number (5441719563).

Almost surely, 2^20212101221 is an apocalyptic number.

It is an amenable number.

20212101221 is a deficient number, since it is larger than the sum of its proper divisors (1554777031).

20212101221 is a wasteful number, since it uses less digits than its factorization.

20212101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1554777030.

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

Adding to 20212101221 its reverse (12210121202), we get a palindrome (32422222423).

The spelling of 20212101221 in words is "twenty billion, two hundred twelve million, one hundred one thousand, two hundred twenty-one".