21342503 has 12 divisors (see below), whose sum is σ = 26413488. Its totient is φ = 16885440.

The previous prime is 21342493. The next prime is 21342511. The reversal of 21342503 is 30524312.

It is a happy number.

It is not a de Polignac number, because 21342503 - 2⁴ = 21342487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342523) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7838 + ... + 10203.

It is an arithmetic number, because the mean of its divisors is an integer number (2201124).

Almost surely, 2^21342503 is an apocalyptic number.

21342503 is a deficient number, since it is larger than the sum of its proper divisors (5070985).

21342503 is a wasteful number, since it uses less digits than its factorization.

21342503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18074 (or 18061 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 21342503 is about 4619.7946924079. The cubic root of 21342503 is about 277.3842408718.

Adding to 21342503 its reverse (30524312), we get a palindrome (51866815).

The spelling of 21342503 in words is "twenty-one million, three hundred forty-two thousand, five hundred three".