20021101221 has 16 divisors (see below), whose sum is σ = 29472468480. Its totient is φ = 11987806320.

The previous prime is 20021101207. The next prime is 20021101237. The reversal of 20021101221 is 12210112002.

It is not a de Polignac number, because 20021101221 - 2⁵ = 20021101189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20021101197 and 20021101206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021101271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3652081 + ... + 3657558.

It is an arithmetic number, because the mean of its divisors is an integer number (1842029280).

Almost surely, 2^20021101221 is an apocalyptic number.

It is an amenable number.

20021101221 is a deficient number, since it is larger than the sum of its proper divisors (9451367259).

20021101221 is a wasteful number, since it uses less digits than its factorization.

20021101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7309736.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20021101221 its reverse (12210112002), we get a palindrome (32231213223).

The spelling of 20021101221 in words is "twenty billion, twenty-one million, one hundred one thousand, two hundred twenty-one".