21361003 has 2 divisors, whose sum is σ = 21361004. Its totient is φ = 21361002.

The previous prime is 21361001. The next prime is 21361013. The reversal of 21361003 is 30016312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21361003 - 2¹ = 21361001 is a prime.

Together with 21361001, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21361001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680501 + 10680502.

It is an arithmetic number, because the mean of its divisors is an integer number (10680502).

Almost surely, 2^21361003 is an apocalyptic number.

21361003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21361003 is an equidigital number, since it uses as much as digits as its factorization.

21361003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 21361003 is about 4621.7965121801. The cubic root of 21361003 is about 277.4643646582.

Adding to 21361003 its reverse (30016312), we get a palindrome (51377315).

It can be divided in two parts, 213 and 61003, that added together give a palindrome (61216).

The spelling of 21361003 in words is "twenty-one million, three hundred sixty-one thousand, three".