21328603 has 2 divisors, whose sum is σ = 21328604. Its totient is φ = 21328602.

The previous prime is 21328597. The next prime is 21328609. The reversal of 21328603 is 30682312.

It is a balanced prime because it is at equal distance from previous prime (21328597) and next prime (21328609).

It is a cyclic number.

It is not a de Polignac number, because 21328603 - 2²¹ = 19231451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21328609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10664301 + 10664302.

It is an arithmetic number, because the mean of its divisors is an integer number (10664302).

Almost surely, 2^21328603 is an apocalyptic number.

21328603 is a deficient number, since it is larger than the sum of its proper divisors (1).

21328603 is an equidigital number, since it uses as much as digits as its factorization.

21328603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21328603 is about 4618.2900515234. The cubic root of 21328603 is about 277.3240092878.

The spelling of 21328603 in words is "twenty-one million, three hundred twenty-eight thousand, six hundred three".