21120001111 has 8 divisors (see below), whose sum is σ = 23474718864. Its totient is φ = 18837736320.

The previous prime is 21120001103. The next prime is 21120001127. The reversal of 21120001111 is 11110002112.

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 21120001111 - 2³ = 21120001103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120001411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18112626 + ... + 18113791.

It is an arithmetic number, because the mean of its divisors is an integer number (2934339858).

Almost surely, 2^21120001111 is an apocalyptic number.

21120001111 is a deficient number, since it is larger than the sum of its proper divisors (2354717753).

21120001111 is a wasteful number, since it uses less digits than its factorization.

21120001111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36226481.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21120001111 its reverse (11110002112), we get a palindrome (32230003223).

The spelling of 21120001111 in words is "twenty-one billion, one hundred twenty million, one thousand, one hundred eleven".