80766439021 has 2 divisors, whose sum is σ = 80766439022. Its totient is φ = 80766439020.

The previous prime is 80766438989. The next prime is 80766439129. The reversal of 80766439021 is 12093466708.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80137683396 + 628755625 = 283086^2 + 25075^2 .

It is a cyclic number.

It is not a de Polignac number, because 80766439021 - 2⁵ = 80766438989 is a prime.

It is a super-2 number, since 2×80766439021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80766439321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40383219510 + 40383219511.

It is an arithmetic number, because the mean of its divisors is an integer number (40383219511).

Almost surely, 2^80766439021 is an apocalyptic number.

It is an amenable number.

80766439021 is a deficient number, since it is larger than the sum of its proper divisors (1).

80766439021 is an equidigital number, since it uses as much as digits as its factorization.

80766439021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 80766439021 in words is "eighty billion, seven hundred sixty-six million, four hundred thirty-nine thousand, twenty-one".