21310003 has 8 divisors (see below), whose sum is σ = 25035696. Its totient is φ = 17882400.

The previous prime is 21309997. The next prime is 21310007. The reversal of 21310003 is 30001312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21310003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21310007) 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 in 7 ways as a sum of consecutive naturals, for example, 74368 + ... + 74653.

It is an arithmetic number, because the mean of its divisors is an integer number (3129462).

Almost surely, 2^21310003 is an apocalyptic number.

21310003 is a deficient number, since it is larger than the sum of its proper divisors (3725693).

21310003 is a wasteful number, since it uses less digits than its factorization.

21310003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149045.

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 21310003 is about 4616.2758799708. The cubic root of 21310003 is about 277.2433706771.

Adding to 21310003 its reverse (30001312), we get a palindrome (51311315).

The spelling of 21310003 in words is "twenty-one million, three hundred ten thousand, three".