21416503 has 2 divisors, whose sum is σ = 21416504. Its totient is φ = 21416502.

The previous prime is 21416491. The next prime is 21416531. The reversal of 21416503 is 30561412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21416503 - 2⁹ = 21415991 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21416543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708251 + 10708252.

It is an arithmetic number, because the mean of its divisors is an integer number (10708252).

Almost surely, 2^21416503 is an apocalyptic number.

21416503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21416503 is an equidigital number, since it uses as much as digits as its factorization.

21416503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21416503 is about 4627.7967760048. The cubic root of 21416503 is about 277.7044587945.

Adding to 21416503 its reverse (30561412), we get a palindrome (51977915).

The spelling of 21416503 in words is "twenty-one million, four hundred sixteen thousand, five hundred three".