21454123 has 2 divisors, whose sum is σ = 21454124. Its totient is φ = 21454122.

The previous prime is 21454099. The next prime is 21454151. The reversal of 21454123 is 32145412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21454123 - 2⁵ = 21454091 is a prime.

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

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21454094 and 21454103.

It is not a weakly prime, because it can be changed into another prime (21454163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727061 + 10727062.

It is an arithmetic number, because the mean of its divisors is an integer number (10727062).

Almost surely, 2^21454123 is an apocalyptic number.

21454123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21454123 is an equidigital number, since it uses as much as digits as its factorization.

21454123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 22.

The square root of 21454123 is about 4631.8595617743. The cubic root of 21454123 is about 277.8669679046.

Adding to 21454123 its reverse (32145412), we get a palindrome (53599535).

The spelling of 21454123 in words is "twenty-one million, four hundred fifty-four thousand, one hundred twenty-three".