21022001111 has 4 divisors (see below), whose sum is σ = 21030504192. Its totient is φ = 21013498032.

The previous prime is 21022001101. The next prime is 21022001153. The reversal of 21022001111 is 11110022012.

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 21022001111 - 2¹⁸ = 21021738967 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022001092 and 21022001101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022001101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4247831 + ... + 4252776.

It is an arithmetic number, because the mean of its divisors is an integer number (5257626048).

Almost surely, 2^21022001111 is an apocalyptic number.

21022001111 is a deficient number, since it is larger than the sum of its proper divisors (8503081).

21022001111 is an equidigital number, since it uses as much as digits as its factorization.

21022001111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8503080.

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

Adding to 21022001111 its reverse (11110022012), we get a palindrome (32132023123).

The spelling of 21022001111 in words is "twenty-one billion, twenty-two million, one thousand, one hundred eleven".