82438243621 has 2 divisors, whose sum is σ = 82438243622. Its totient is φ = 82438243620.

The previous prime is 82438243619. The next prime is 82438243709. The reversal of 82438243621 is 12634283428.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57545292996 + 24892950625 = 239886^2 + 157775^2 .

It is a cyclic number.

It is not a de Polignac number, because 82438243621 - 2¹ = 82438243619 is a prime.

It is a super-2 number, since 2×82438243621² (a number of 23 digits) contains 22 as substring.

Together with 82438243619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82438213621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41219121810 + 41219121811.

It is an arithmetic number, because the mean of its divisors is an integer number (41219121811).

Almost surely, 2^82438243621 is an apocalyptic number.

It is an amenable number.

82438243621 is a deficient number, since it is larger than the sum of its proper divisors (1).

82438243621 is an equidigital number, since it uses as much as digits as its factorization.

82438243621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 442368, while the sum is 43.

The spelling of 82438243621 in words is "eighty-two billion, four hundred thirty-eight million, two hundred forty-three thousand, six hundred twenty-one".