21435320201 has 2 divisors, whose sum is σ = 21435320202. Its totient is φ = 21435320200.

The previous prime is 21435320197. The next prime is 21435320209. The reversal of 21435320201 is 10202353412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16113763600 + 5321556601 = 126940^2 + 72949^2 .

It is a cyclic number.

It is not a de Polignac number, because 21435320201 - 2² = 21435320197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21435320209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717660100 + 10717660101.

It is an arithmetic number, because the mean of its divisors is an integer number (10717660101).

Almost surely, 2^21435320201 is an apocalyptic number.

It is an amenable number.

21435320201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21435320201 is an equidigital number, since it uses as much as digits as its factorization.

21435320201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21435320201 its reverse (10202353412), we get a palindrome (31637673613).

The spelling of 21435320201 in words is "twenty-one billion, four hundred thirty-five million, three hundred twenty thousand, two hundred one".