21286735837 has 2 divisors, whose sum is σ = 21286735838. Its totient is φ = 21286735836.

The previous prime is 21286735829. The next prime is 21286735853. The reversal of 21286735837 is 73853768212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12377452516 + 8909283321 = 111254^2 + 94389^2 .

It is a cyclic number.

It is not a de Polignac number, because 21286735837 - 2³ = 21286735829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21286732837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10643367918 + 10643367919.

It is an arithmetic number, because the mean of its divisors is an integer number (10643367919).

Almost surely, 2^21286735837 is an apocalyptic number.

It is an amenable number.

21286735837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21286735837 is an equidigital number, since it uses as much as digits as its factorization.

21286735837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3386880, while the sum is 52.

The spelling of 21286735837 in words is "twenty-one billion, two hundred eighty-six million, seven hundred thirty-five thousand, eight hundred thirty-seven".