20021011121 has 4 divisors (see below), whose sum is σ = 20021337600. Its totient is φ = 20020684644.

The previous prime is 20021011103. The next prime is 20021011229. The reversal of 20021011121 is 12111012002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021011121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20021091121) 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, 40481 + ... + 204158.

It is an arithmetic number, because the mean of its divisors is an integer number (5005334400).

Almost surely, 2^20021011121 is an apocalyptic number.

It is an amenable number.

20021011121 is a deficient number, since it is larger than the sum of its proper divisors (326479).

20021011121 is an equidigital number, since it uses as much as digits as its factorization.

20021011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326478.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20021011121 its reverse (12111012002), we get a palindrome (32132023123).

The spelling of 20021011121 in words is "twenty billion, twenty-one million, eleven thousand, one hundred twenty-one".