20021121221 has 8 divisors (see below), whose sum is σ = 21231814464. Its totient is φ = 18814092480.

The previous prime is 20021121217. The next prime is 20021121269. The reversal of 20021121221 is 12212112002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20021121221 - 2² = 20021121217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021121196 and 20021121205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021121521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 904865 + ... + 926726.

It is an arithmetic number, because the mean of its divisors is an integer number (2653976808).

Almost surely, 2^20021121221 is an apocalyptic number.

It is an amenable number.

20021121221 is a deficient number, since it is larger than the sum of its proper divisors (1210693243).

20021121221 is a wasteful number, since it uses less digits than its factorization.

20021121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1832251.

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

Adding to 20021121221 its reverse (12212112002), we get a palindrome (32233233223).

The spelling of 20021121221 in words is "twenty billion, twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".