20211121021 has 8 divisors (see below), whose sum is σ = 24875225984. Its totient is φ = 15991216560.

The previous prime is 20211121019. The next prime is 20211121037. The reversal of 20211121021 is 12012111202.

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 20211121021 - 2¹ = 20211121019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a junction number, because it is equal to n+sod(n) for n = 20211120992 and 20211121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211121121) 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, 111050025 + ... + 111050206.

It is an arithmetic number, because the mean of its divisors is an integer number (3109403248).

Almost surely, 2^20211121021 is an apocalyptic number.

It is an amenable number.

20211121021 is a deficient number, since it is larger than the sum of its proper divisors (4664104963).

20211121021 is a wasteful number, since it uses less digits than its factorization.

20211121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222100251.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20211121021 its reverse (12012111202), we get a palindrome (32223232223).

The spelling of 20211121021 in words is "twenty billion, two hundred eleven million, one hundred twenty-one thousand, twenty-one".