21286342249 has 2 divisors, whose sum is σ = 21286342250. Its totient is φ = 21286342248.

The previous prime is 21286342241. The next prime is 21286342261. The reversal of 21286342249 is 94224368212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20119436649 + 1166905600 = 141843^2 + 34160^2 .

It is a cyclic number.

It is not a de Polignac number, because 21286342249 - 2³ = 21286342241 is a prime.

It is not a weakly prime, because it can be changed into another prime (21286342241) 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, 10643171124 + 10643171125.

It is an arithmetic number, because the mean of its divisors is an integer number (10643171125).

Almost surely, 2^21286342249 is an apocalyptic number.

It is an amenable number.

21286342249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21286342249 is an equidigital number, since it uses as much as digits as its factorization.

21286342249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 43.

The spelling of 21286342249 in words is "twenty-one billion, two hundred eighty-six million, three hundred forty-two thousand, two hundred forty-nine".