80684521 has 2 divisors, whose sum is σ = 80684522. Its totient is φ = 80684520.

The previous prime is 80684519. The next prime is 80684561. The reversal of 80684521 is 12548608.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51912025 + 28772496 = 7205^2 + 5364^2 .

It is a cyclic number.

It is not a de Polignac number, because 80684521 - 2¹ = 80684519 is a prime.

Together with 80684519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (80684561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40342260 + 40342261.

It is an arithmetic number, because the mean of its divisors is an integer number (40342261).

Almost surely, 2^80684521 is an apocalyptic number.

It is an amenable number.

80684521 is a deficient number, since it is larger than the sum of its proper divisors (1).

80684521 is an equidigital number, since it uses as much as digits as its factorization.

80684521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 80684521 is about 8982.4562899020. The cubic root of 80684521 is about 432.1124125185.

The spelling of 80684521 in words is "eighty million, six hundred eighty-four thousand, five hundred twenty-one".