21030120111 has 64 divisors (see below), whose sum is σ = 38021630976. Its totient is φ = 9984384000.

The previous prime is 21030120109. The next prime is 21030120149. The reversal of 21030120111 is 11102103012.

It is not a de Polignac number, because 21030120111 - 2¹ = 21030120109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030120511) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 268635 + ... + 337971.

It is an arithmetic number, because the mean of its divisors is an integer number (594087984).

Almost surely, 2^21030120111 is an apocalyptic number.

21030120111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21030120111 is a deficient number, since it is larger than the sum of its proper divisors (16991510865).

21030120111 is a wasteful number, since it uses less digits than its factorization.

21030120111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69472.

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21030120111 its reverse (11102103012), we get a palindrome (32132223123).

It can be divided in two parts, 21030 and 120111, that added together give a palindrome (141141).

The spelling of 21030120111 in words is "twenty-one billion, thirty million, one hundred twenty thousand, one hundred eleven".