21124097993 has 2 divisors, whose sum is σ = 21124097994. Its totient is φ = 21124097992.

The previous prime is 21124097987. The next prime is 21124098001. The reversal of 21124097993 is 39979042112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20723617849 + 400480144 = 143957^2 + 20012^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124097993 - 2⁴ = 21124097977 is a prime.

It is not a weakly prime, because it can be changed into another prime (21124097923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562048996 + 10562048997.

It is an arithmetic number, because the mean of its divisors is an integer number (10562048997).

Almost surely, 2^21124097993 is an apocalyptic number.

It is an amenable number.

21124097993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124097993 is an equidigital number, since it uses as much as digits as its factorization.

21124097993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 47.

The spelling of 21124097993 in words is "twenty-one billion, one hundred twenty-four million, ninety-seven thousand, nine hundred ninety-three".