21353342281 has 2 divisors, whose sum is σ = 21353342282. Its totient is φ = 21353342280.

The previous prime is 21353342243. The next prime is 21353342359. The reversal of 21353342281 is 18224335312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14451886656 + 6901455625 = 120216^2 + 83075^2 .

It is a cyclic number.

It is not a de Polignac number, because 21353342281 - 2⁹ = 21353341769 is a prime.

It is a super-2 number, since 2×21353342281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21353342081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676671140 + 10676671141.

It is an arithmetic number, because the mean of its divisors is an integer number (10676671141).

Almost surely, 2^21353342281 is an apocalyptic number.

It is an amenable number.

21353342281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21353342281 is an equidigital number, since it uses as much as digits as its factorization.

21353342281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 34.

Adding to 21353342281 its reverse (18224335312), we get a palindrome (39577677593).

The spelling of 21353342281 in words is "twenty-one billion, three hundred fifty-three million, three hundred forty-two thousand, two hundred eighty-one".