21130111 has 2 divisors, whose sum is σ = 21130112. Its totient is φ = 21130110.

The previous prime is 21130079. The next prime is 21130231. The reversal of 21130111 is 11103112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21130111 - 2⁵ = 21130079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565055 + 10565056.

It is an arithmetic number, because the mean of its divisors is an integer number (10565056).

Almost surely, 2^21130111 is an apocalyptic number.

21130111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130111 is an equidigital number, since it uses as much as digits as its factorization.

21130111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6, while the sum is 10.

The square root of 21130111 is about 4596.7500475880. The cubic root of 21130111 is about 276.4610328256.

Adding to 21130111 its reverse (11103112), we get a palindrome (32233223).

The spelling of 21130111 in words is "twenty-one million, one hundred thirty thousand, one hundred eleven".