21384503 has 16 divisors (see below), whose sum is σ = 25643520. Its totient is φ = 17435616.

The previous prime is 21384479. The next prime is 21384509. The reversal of 21384503 is 30548312.

It is a cyclic number.

It is not a de Polignac number, because 21384503 - 2¹⁶ = 21318967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384509) 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 15 ways as a sum of consecutive naturals, for example, 50828 + ... + 51246.

It is an arithmetic number, because the mean of its divisors is an integer number (1602720).

Almost surely, 2^21384503 is an apocalyptic number.

21384503 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21384503 is a deficient number, since it is larger than the sum of its proper divisors (4259017).

21384503 is a wasteful number, since it uses less digits than its factorization.

21384503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21384503 is about 4624.3381148009. The cubic root of 21384503 is about 277.5660768439.

The spelling of 21384503 in words is "twenty-one million, three hundred eighty-four thousand, five hundred three".