21215103 has 16 divisors (see below), whose sum is σ = 34814976. Its totient is φ = 11190240.

The previous prime is 21215101. The next prime is 21215107. The reversal of 21215103 is 30151212.

It is not a de Polignac number, because 21215103 - 2¹ = 21215101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21215101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38583 + ... + 39128.

It is an arithmetic number, because the mean of its divisors is an integer number (2175936).

Almost surely, 2^21215103 is an apocalyptic number.

21215103 is a deficient number, since it is larger than the sum of its proper divisors (13599873).

21215103 is a wasteful number, since it uses less digits than its factorization.

21215103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77734.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21215103 is about 4605.9855622874. The cubic root of 21215103 is about 276.8312082310.

Adding to 21215103 its reverse (30151212), we get a palindrome (51366315).

The spelling of 21215103 in words is "twenty-one million, two hundred fifteen thousand, one hundred three".