87205309 has 2 divisors, whose sum is σ = 87205310. Its totient is φ = 87205308.

The previous prime is 87205301. The next prime is 87205343. The reversal of 87205309 is 90350278.

It is an a-pointer prime, because the next prime (87205343) can be obtained adding 87205309 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80460900 + 6744409 = 8970^2 + 2597^2 .

It is a cyclic number.

It is not a de Polignac number, because 87205309 - 2³ = 87205301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87205301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43602654 + 43602655.

It is an arithmetic number, because the mean of its divisors is an integer number (43602655).

Almost surely, 2^87205309 is an apocalyptic number.

It is an amenable number.

87205309 is a deficient number, since it is larger than the sum of its proper divisors (1).

87205309 is an equidigital number, since it uses as much as digits as its factorization.

87205309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 87205309 is about 9338.3782853341. The cubic root of 87205309 is about 443.4530454161.

The spelling of 87205309 in words is "eighty-seven million, two hundred five thousand, three hundred nine".