21202324657 has 2 divisors, whose sum is σ = 21202324658. Its totient is φ = 21202324656.

The previous prime is 21202324621. The next prime is 21202324679. The reversal of 21202324657 is 75642320212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21177234576 + 25090081 = 145524^2 + 5009^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202324657 - 2²⁷ = 21068106929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21202324697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601162328 + 10601162329.

It is an arithmetic number, because the mean of its divisors is an integer number (10601162329).

Almost surely, 2^21202324657 is an apocalyptic number.

It is an amenable number.

21202324657 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202324657 is an equidigital number, since it uses as much as digits as its factorization.

21202324657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 34.

Adding to 21202324657 its reverse (75642320212), we get a palindrome (96844644869).

The spelling of 21202324657 in words is "twenty-one billion, two hundred two million, three hundred twenty-four thousand, six hundred fifty-seven".