21337283809 has 2 divisors, whose sum is σ = 21337283810. Its totient is φ = 21337283808.

The previous prime is 21337283719. The next prime is 21337283813. The reversal of 21337283809 is 90838273312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13676133025 + 7661150784 = 116945^2 + 87528^2 .

It is a cyclic number.

It is not a de Polignac number, because 21337283809 - 2¹¹ = 21337281761 is a prime.

It is not a weakly prime, because it can be changed into another prime (21337283819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10668641904 + 10668641905.

It is an arithmetic number, because the mean of its divisors is an integer number (10668641905).

Almost surely, 2^21337283809 is an apocalyptic number.

It is an amenable number.

21337283809 is a deficient number, since it is larger than the sum of its proper divisors (1).

21337283809 is an equidigital number, since it uses as much as digits as its factorization.

21337283809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 21337283809 in words is "twenty-one billion, three hundred thirty-seven million, two hundred eighty-three thousand, eight hundred nine".