21258443833349 has 2 divisors, whose sum is σ = 21258443833350. Its totient is φ = 21258443833348.

The previous prime is 21258443833337. The next prime is 21258443833379. The reversal of 21258443833349 is 94333834485212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21118712160100 + 139731673249 = 4595510^2 + 373807^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21258443833349 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21258443833379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10629221916674 + 10629221916675.

It is an arithmetic number, because the mean of its divisors is an integer number (10629221916675).

Almost surely, 2^{21258443833349} is an apocalyptic number.

It is an amenable number.

21258443833349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21258443833349 is an equidigital number, since it uses as much as digits as its factorization.

21258443833349 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59719680, while the sum is 59.

The spelling of 21258443833349 in words is "twenty-one trillion, two hundred fifty-eight billion, four hundred forty-three million, eight hundred thirty-three thousand, three hundred forty-nine".