80345821 has 2 divisors, whose sum is σ = 80345822. Its totient is φ = 80345820.

The previous prime is 80345819. The next prime is 80345873. The reversal of 80345821 is 12854308.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57592921 + 22752900 = 7589^2 + 4770^2 .

It is a cyclic number.

It is not a de Polignac number, because 80345821 - 2¹ = 80345819 is a prime.

Together with 80345819, 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 (80345021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40172910 + 40172911.

It is an arithmetic number, because the mean of its divisors is an integer number (40172911).

Almost surely, 2^80345821 is an apocalyptic number.

It is an amenable number.

80345821 is a deficient number, since it is larger than the sum of its proper divisors (1).

80345821 is an equidigital number, since it uses as much as digits as its factorization.

80345821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 80345821 is about 8963.5830447428. The cubic root of 80345821 is about 431.5069194842.

The spelling of 80345821 in words is "eighty million, three hundred forty-five thousand, eight hundred twenty-one".