21648001 has 2 divisors, whose sum is σ = 21648002. Its totient is φ = 21648000.

The previous prime is 21647993. The next prime is 21648047. The reversal of 21648001 is 10084612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 303601 = 4620^2 + 551^2 .

It is a cyclic number.

It is not a de Polignac number, because 21648001 - 2³ = 21647993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21648301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10824000 + 10824001.

It is an arithmetic number, because the mean of its divisors is an integer number (10824001).

Almost surely, 2^21648001 is an apocalyptic number.

It is an amenable number.

21648001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21648001 is an equidigital number, since it uses as much as digits as its factorization.

21648001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21648001 is about 4652.7412350140. The cubic root of 21648001 is about 278.7014745241.

The spelling of 21648001 in words is "twenty-one million, six hundred forty-eight thousand, one".