80821457 has 2 divisors, whose sum is σ = 80821458. Its totient is φ = 80821456.

The previous prime is 80821453. The next prime is 80821469. The reversal of 80821457 is 75412808.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76457536 + 4363921 = 8744^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 80821457 - 2² = 80821453 is a prime.

It is not a weakly prime, because it can be changed into another prime (80821453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40410728 + 40410729.

It is an arithmetic number, because the mean of its divisors is an integer number (40410729).

Almost surely, 2^80821457 is an apocalyptic number.

It is an amenable number.

80821457 is a deficient number, since it is larger than the sum of its proper divisors (1).

80821457 is an equidigital number, since it uses as much as digits as its factorization.

80821457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 80821457 is about 8990.0754724307. The cubic root of 80821457 is about 432.3567315904.

The spelling of 80821457 in words is "eighty million, eight hundred twenty-one thousand, four hundred fifty-seven".