21448451 has 2 divisors, whose sum is σ = 21448452. Its totient is φ = 21448450.

The previous prime is 21448433. The next prime is 21448457. The reversal of 21448451 is 15484412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21448451 - 2¹⁰ = 21447427 is a prime.

It is not a weakly prime, because it can be changed into another prime (21448457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724225 + 10724226.

It is an arithmetic number, because the mean of its divisors is an integer number (10724226).

Almost surely, 2^21448451 is an apocalyptic number.

21448451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21448451 is an equidigital number, since it uses as much as digits as its factorization.

21448451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5120, while the sum is 29.

The square root of 21448451 is about 4631.2472402151. The cubic root of 21448451 is about 277.8424784338.

The spelling of 21448451 in words is "twenty-one million, four hundred forty-eight thousand, four hundred fifty-one".