80986978021 has 2 divisors, whose sum is σ = 80986978022. Its totient is φ = 80986978020.

The previous prime is 80986978019. The next prime is 80986978031. The reversal of 80986978021 is 12087968908.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79202844900 + 1784133121 = 281430^2 + 42239^2 .

It is a cyclic number.

It is not a de Polignac number, because 80986978021 - 2¹ = 80986978019 is a prime.

It is a super-4 number, since 4×80986978021⁴ (a number of 45 digits) contains 4444 as substring.

Together with 80986978019, 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 (80986978001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40493489010 + 40493489011.

It is an arithmetic number, because the mean of its divisors is an integer number (40493489011).

Almost surely, 2^80986978021 is an apocalyptic number.

It is an amenable number.

80986978021 is a deficient number, since it is larger than the sum of its proper divisors (1).

80986978021 is an equidigital number, since it uses as much as digits as its factorization.

80986978021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3483648, while the sum is 58.

The spelling of 80986978021 in words is "eighty billion, nine hundred eighty-six million, nine hundred seventy-eight thousand, twenty-one".