20421011211 has 4 divisors (see below), whose sum is σ = 27228014952. Its totient is φ = 13614007472.

The previous prime is 20421011209. The next prime is 20421011231. The reversal of 20421011211 is 11211012402.

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 20421011211 - 2¹ = 20421011209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20421011231) 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, 3403501866 + ... + 3403501871.

It is an arithmetic number, because the mean of its divisors is an integer number (6807003738).

Almost surely, 2^20421011211 is an apocalyptic number.

20421011211 is a deficient number, since it is larger than the sum of its proper divisors (6807003741).

20421011211 is an equidigital number, since it uses as much as digits as its factorization.

20421011211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6807003740.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20421011211 its reverse (11211012402), we get a palindrome (31632023613).

The spelling of 20421011211 in words is "twenty billion, four hundred twenty-one million, eleven thousand, two hundred eleven".