21454943 has 2 divisors, whose sum is σ = 21454944. Its totient is φ = 21454942.

The previous prime is 21454903. The next prime is 21454949. The reversal of 21454943 is 34945412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21454943 - 2⁶ = 21454879 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 (21454949) 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 as a sum of consecutive naturals, namely, 10727471 + 10727472.

It is an arithmetic number, because the mean of its divisors is an integer number (10727472).

Almost surely, 2^21454943 is an apocalyptic number.

21454943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21454943 is an equidigital number, since it uses as much as digits as its factorization.

21454943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The square root of 21454943 is about 4631.9480782928. The cubic root of 21454943 is about 277.8705079857.

The spelling of 21454943 in words is "twenty-one million, four hundred fifty-four thousand, nine hundred forty-three".