21648079 has 2 divisors, whose sum is σ = 21648080. Its totient is φ = 21648078.

The previous prime is 21648047. The next prime is 21648127. The reversal of 21648079 is 97084612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21648079 - 2⁵ = 21648047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21643079) 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, 10824039 + 10824040.

It is an arithmetic number, because the mean of its divisors is an integer number (10824040).

Almost surely, 2^21648079 is an apocalyptic number.

21648079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21648079 is an equidigital number, since it uses as much as digits as its factorization.

21648079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 21648079 is about 4652.7496171619. The cubic root of 21648079 is about 278.7018092538.

The spelling of 21648079 in words is "twenty-one million, six hundred forty-eight thousand, seventy-nine".