21582775349 has 2 divisors, whose sum is σ = 21582775350. Its totient is φ = 21582775348.

The previous prime is 21582775343. The next prime is 21582775363. The reversal of 21582775349 is 94357728512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21369177124 + 213598225 = 146182^2 + 14615^2 .

It is a cyclic number.

It is not a de Polignac number, because 21582775349 - 2³² = 17287808053 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 21582775349.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21582775343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10791387674 + 10791387675.

It is an arithmetic number, because the mean of its divisors is an integer number (10791387675).

Almost surely, 2^21582775349 is an apocalyptic number.

It is an amenable number.

21582775349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21582775349 is an equidigital number, since it uses as much as digits as its factorization.

21582775349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 53.

The spelling of 21582775349 in words is "twenty-one billion, five hundred eighty-two million, seven hundred seventy-five thousand, three hundred forty-nine".