21745003 has 4 divisors (see below), whose sum is σ = 24851440. Its totient is φ = 18638568.

The previous prime is 21745001. The next prime is 21745007. The reversal of 21745003 is 30054712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21745003 - 2¹ = 21745001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21745001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1553208 + ... + 1553221.

It is an arithmetic number, because the mean of its divisors is an integer number (6212860).

Almost surely, 2^21745003 is an apocalyptic number.

21745003 is a deficient number, since it is larger than the sum of its proper divisors (3106437).

21745003 is an equidigital number, since it uses as much as digits as its factorization.

21745003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3106436.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21745003 is about 4663.1537611363. The cubic root of 21745003 is about 279.1171298555.

Adding to 21745003 its reverse (30054712), we get a palindrome (51799715).

The spelling of 21745003 in words is "twenty-one million, seven hundred forty-five thousand, three".