21140111 has 4 divisors (see below), whose sum is σ = 21200352. Its totient is φ = 21079872.

The previous prime is 21140107. The next prime is 21140123. The reversal of 21140111 is 11104112.

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 21140111 - 2² = 21140107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21140092 and 21140101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29591 + ... + 30296.

It is an arithmetic number, because the mean of its divisors is an integer number (5300088).

Almost surely, 2^21140111 is an apocalyptic number.

21140111 is a deficient number, since it is larger than the sum of its proper divisors (60241).

21140111 is an equidigital number, since it uses as much as digits as its factorization.

21140111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60240.

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

The square root of 21140111 is about 4597.8376439365. The cubic root of 21140111 is about 276.5046384384.

Adding to 21140111 its reverse (11104112), we get a palindrome (32244223).

The spelling of 21140111 in words is "twenty-one million, one hundred forty thousand, one hundred eleven".