21223793 has 2 divisors, whose sum is σ = 21223794. Its totient is φ = 21223792.

The previous prime is 21223789. The next prime is 21223823. The reversal of 21223793 is 39732212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13890529 + 7333264 = 3727^2 + 2708^2 .

It is a cyclic number.

It is not a de Polignac number, because 21223793 - 2² = 21223789 is a prime.

It is not a weakly prime, because it can be changed into another prime (21223723) 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, 10611896 + 10611897.

It is an arithmetic number, because the mean of its divisors is an integer number (10611897).

Almost surely, 2^21223793 is an apocalyptic number.

It is an amenable number.

21223793 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223793 is an equidigital number, since it uses as much as digits as its factorization.

21223793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 29.

The square root of 21223793 is about 4606.9288034438. The cubic root of 21223793 is about 276.8690010369.

The spelling of 21223793 in words is "twenty-one million, two hundred twenty-three thousand, seven hundred ninety-three".