21103711 has 2 divisors, whose sum is σ = 21103712. Its totient is φ = 21103710.

The previous prime is 21103697. The next prime is 21103721. The reversal of 21103711 is 11730112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21103711 - 2⁵ = 21103679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21103721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551855 + 10551856.

It is an arithmetic number, because the mean of its divisors is an integer number (10551856).

Almost surely, 2^21103711 is an apocalyptic number.

21103711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103711 is an equidigital number, since it uses as much as digits as its factorization.

21103711 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 16.

The square root of 21103711 is about 4593.8775560522. The cubic root of 21103711 is about 276.3458478652.

Adding to 21103711 its reverse (11730112), we get a palindrome (32833823).

The spelling of 21103711 in words is "twenty-one million, one hundred three thousand, seven hundred eleven".