21436200161 has 2 divisors, whose sum is σ = 21436200162. Its totient is φ = 21436200160.

The previous prime is 21436200151. The next prime is 21436200187. The reversal of 21436200161 is 16100263412.

It is an a-pointer prime, because the next prime (21436200187) can be obtained adding 21436200161 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16007310400 + 5428889761 = 126520^2 + 73681^2 .

It is a cyclic number.

It is not a de Polignac number, because 21436200161 - 2¹⁴ = 21436183777 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21436200161.

It is not a weakly prime, because it can be changed into another prime (21436200131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718100080 + 10718100081.

It is an arithmetic number, because the mean of its divisors is an integer number (10718100081).

Almost surely, 2^21436200161 is an apocalyptic number.

It is an amenable number.

21436200161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21436200161 is an equidigital number, since it uses as much as digits as its factorization.

21436200161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 21436200161 its reverse (16100263412), we get a palindrome (37536463573).

The spelling of 21436200161 in words is "twenty-one billion, four hundred thirty-six million, two hundred thousand, one hundred sixty-one".