80123821 has 2 divisors, whose sum is σ = 80123822. Its totient is φ = 80123820.

The previous prime is 80123777. The next prime is 80123831. The reversal of 80123821 is 12832108.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69973225 + 10150596 = 8365^2 + 3186^2 .

It is a cyclic number.

It is not a de Polignac number, because 80123821 - 2¹⁷ = 79992749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80123831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40061910 + 40061911.

It is an arithmetic number, because the mean of its divisors is an integer number (40061911).

Almost surely, 2^80123821 is an apocalyptic number.

It is an amenable number.

80123821 is a deficient number, since it is larger than the sum of its proper divisors (1).

80123821 is an equidigital number, since it uses as much as digits as its factorization.

80123821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 80123821 is about 8951.1910380686. The cubic root of 80123821 is about 431.1091269620.

Adding to 80123821 its reverse (12832108), we get a palindrome (92955929).

The spelling of 80123821 in words is "eighty million, one hundred twenty-three thousand, eight hundred twenty-one".