20021021011 has 4 divisors (see below), whose sum is σ = 20034432432. Its totient is φ = 20007609592.

The previous prime is 20021020991. The next prime is 20021021021. The reversal of 20021021011 is 11012012002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021021011 - 2¹³ = 20021012819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021021021) 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, 6703471 + ... + 6706456.

It is an arithmetic number, because the mean of its divisors is an integer number (5008608108).

Almost surely, 2^20021021011 is an apocalyptic number.

20021021011 is a deficient number, since it is larger than the sum of its proper divisors (13411421).

20021021011 is a wasteful number, since it uses less digits than its factorization.

20021021011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13411420.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20021021011 its reverse (11012012002), we get a palindrome (31033033013).

Subtracting from 20021021011 its reverse (11012012002), we obtain a palindrome (9009009009).

The spelling of 20021021011 in words is "twenty billion, twenty-one million, twenty-one thousand, eleven".