21354603 has 16 divisors (see below), whose sum is σ = 29880576. Its totient is φ = 13539680.

The previous prime is 21354589. The next prime is 21354653. The reversal of 21354603 is 30645312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21354603 - 2¹³ = 21346411 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21354653) 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, 12808 + ... + 14378.

It is an arithmetic number, because the mean of its divisors is an integer number (1867536).

Almost surely, 2^21354603 is an apocalyptic number.

21354603 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21354603 is a deficient number, since it is larger than the sum of its proper divisors (8525973).

21354603 is a wasteful number, since it uses less digits than its factorization.

21354603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1794.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 21354603 is about 4621.1040888515. The cubic root of 21354603 is about 277.4366513947.

Adding to 21354603 its reverse (30645312), we get a palindrome (51999915).

The spelling of 21354603 in words is "twenty-one million, three hundred fifty-four thousand, six hundred three".