21284801 has 2 divisors, whose sum is σ = 21284802. Its totient is φ = 21284800.

The previous prime is 21284797. The next prime is 21284839. The reversal of 21284801 is 10848212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21169201 + 115600 = 4601^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 21284801 - 2² = 21284797 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21284401) 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, 10642400 + 10642401.

It is an arithmetic number, because the mean of its divisors is an integer number (10642401).

Almost surely, 2^21284801 is an apocalyptic number.

It is an amenable number.

21284801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21284801 is an equidigital number, since it uses as much as digits as its factorization.

21284801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 21284801 is about 4613.5453828916. The cubic root of 21284801 is about 277.1340347996.

The spelling of 21284801 in words is "twenty-one million, two hundred eighty-four thousand, eight hundred one".