80782639781 has 2 divisors, whose sum is σ = 80782639782. Its totient is φ = 80782639780.

The previous prime is 80782639733. The next prime is 80782639783. The reversal of 80782639781 is 18793628708.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69163740100 + 11618899681 = 262990^2 + 107791^2 .

It is a cyclic number.

It is not a de Polignac number, because 80782639781 - 2²² = 80778445477 is a prime.

It is a super-2 number, since 2×80782639781² (a number of 23 digits) contains 22 as substring.

Together with 80782639783, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 80782639781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80782639783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40391319890 + 40391319891.

It is an arithmetic number, because the mean of its divisors is an integer number (40391319891).

Almost surely, 2^80782639781 is an apocalyptic number.

It is an amenable number.

80782639781 is a deficient number, since it is larger than the sum of its proper divisors (1).

80782639781 is an equidigital number, since it uses as much as digits as its factorization.

80782639781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8128512, while the sum is 59.

The spelling of 80782639781 in words is "eighty billion, seven hundred eighty-two million, six hundred thirty-nine thousand, seven hundred eighty-one".