21111473 has 2 divisors, whose sum is σ = 21111474. Its totient is φ = 21111472.

The previous prime is 21111463. The next prime is 21111479. The reversal of 21111473 is 37411112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21003889 + 107584 = 4583^2 + 328^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111473 - 2⁴ = 21111457 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555736 + 10555737.

It is an arithmetic number, because the mean of its divisors is an integer number (10555737).

Almost surely, 2^21111473 is an apocalyptic number.

It is an amenable number.

21111473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111473 is an equidigital number, since it uses as much as digits as its factorization.

21111473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 168, while the sum is 20.

The square root of 21111473 is about 4594.7222984637. The cubic root of 21111473 is about 276.3797239537.

Adding to 21111473 its reverse (37411112), we get a palindrome (58522585).

The spelling of 21111473 in words is "twenty-one million, one hundred eleven thousand, four hundred seventy-three".