21066224393 has 2 divisors, whose sum is σ = 21066224394. Its totient is φ = 21066224392.

The previous prime is 21066224383. The next prime is 21066224447. The reversal of 21066224393 is 39342266012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17848158409 + 3218065984 = 133597^2 + 56728^2 .

It is a cyclic number.

It is not a de Polignac number, because 21066224393 - 2³⁰ = 19992482569 is a prime.

It is not a weakly prime, because it can be changed into another prime (21066224323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533112196 + 10533112197.

It is an arithmetic number, because the mean of its divisors is an integer number (10533112197).

Almost surely, 2^21066224393 is an apocalyptic number.

It is an amenable number.

21066224393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066224393 is an equidigital number, since it uses as much as digits as its factorization.

21066224393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 38.

The spelling of 21066224393 in words is "twenty-one billion, sixty-six million, two hundred twenty-four thousand, three hundred ninety-three".