21385003 has 4 divisors (see below), whose sum is σ = 21474720. Its totient is φ = 21295288.

The previous prime is 21384991. The next prime is 21385057. The reversal of 21385003 is 30058312.

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 21385003 - 2⁵ = 21384971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21385103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44500 + ... + 44977.

It is an arithmetic number, because the mean of its divisors is an integer number (5368680).

Almost surely, 2^21385003 is an apocalyptic number.

21385003 is a deficient number, since it is larger than the sum of its proper divisors (89717).

21385003 is an equidigital number, since it uses as much as digits as its factorization.

21385003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89716.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21385003 is about 4624.3921762757. The cubic root of 21385003 is about 277.5682401232.

The spelling of 21385003 in words is "twenty-one million, three hundred eighty-five thousand, three".