21136603 has 2 divisors, whose sum is σ = 21136604. Its totient is φ = 21136602.

The previous prime is 21136601. The next prime is 21136613. The reversal of 21136603 is 30663112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21136603 - 2¹ = 21136601 is a prime.

Together with 21136601, it forms a pair of twin primes.

It is equal to p_1338061 and since 21136603 and 1338061 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21136601) 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 as a sum of consecutive naturals, namely, 10568301 + 10568302.

It is an arithmetic number, because the mean of its divisors is an integer number (10568302).

Almost surely, 2^21136603 is an apocalyptic number.

21136603 is a deficient number, since it is larger than the sum of its proper divisors (1).

21136603 is an equidigital number, since it uses as much as digits as its factorization.

21136603 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21136603 is about 4597.4561444347. The cubic root of 21136603 is about 276.4893431556.

Adding to 21136603 its reverse (30663112), we get a palindrome (51799715).

The spelling of 21136603 in words is "twenty-one million, one hundred thirty-six thousand, six hundred three".