21456103 has 2 divisors, whose sum is σ = 21456104. Its totient is φ = 21456102.

The previous prime is 21456089. The next prime is 21456107. The reversal of 21456103 is 30165412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21456103 - 2²¹ = 19358951 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21456107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10728051 + 10728052.

It is an arithmetic number, because the mean of its divisors is an integer number (10728052).

Almost surely, 2^21456103 is an apocalyptic number.

21456103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21456103 is an equidigital number, since it uses as much as digits as its factorization.

21456103 is an evil number, because the sum of its binary digits is even.

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

The square root of 21456103 is about 4632.0732938934. The cubic root of 21456103 is about 277.8755157514.

The spelling of 21456103 in words is "twenty-one million, four hundred fifty-six thousand, one hundred three".