79788366521 has 2 divisors, whose sum is σ = 79788366522. Its totient is φ = 79788366520.

The previous prime is 79788366467. The next prime is 79788366523. The reversal of 79788366521 is 12566388797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67112083600 + 12676282921 = 259060^2 + 112589^2 .

It is a cyclic number.

It is not a de Polignac number, because 79788366521 - 2¹⁸ = 79788104377 is a prime.

It is a super-3 number, since 3×79788366521³ (a number of 34 digits) contains 333 as substring.

Together with 79788366523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (79788366523) 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, 39894183260 + 39894183261.

It is an arithmetic number, because the mean of its divisors is an integer number (39894183261).

Almost surely, 2^79788366521 is an apocalyptic number.

It is an amenable number.

79788366521 is a deficient number, since it is larger than the sum of its proper divisors (1).

79788366521 is an equidigital number, since it uses as much as digits as its factorization.

79788366521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30481920, while the sum is 62.

The spelling of 79788366521 in words is "seventy-nine billion, seven hundred eighty-eight million, three hundred sixty-six thousand, five hundred twenty-one".