81560569 has 2 divisors, whose sum is σ = 81560570. Its totient is φ = 81560568.

The previous prime is 81560539. The next prime is 81560623. The reversal of 81560569 is 96506518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55428025 + 26132544 = 7445^2 + 5112^2 .

It is a cyclic number.

It is not a de Polignac number, because 81560569 - 2¹³ = 81552377 is a prime.

It is a super-2 number, since 2×81560569² = 13304252831207522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81560539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40780284 + 40780285.

It is an arithmetic number, because the mean of its divisors is an integer number (40780285).

Almost surely, 2^81560569 is an apocalyptic number.

It is an amenable number.

81560569 is a deficient number, since it is larger than the sum of its proper divisors (1).

81560569 is an equidigital number, since it uses as much as digits as its factorization.

81560569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64800, while the sum is 40.

The square root of 81560569 is about 9031.0890262471. The cubic root of 81560569 is about 433.6707013137.

The spelling of 81560569 in words is "eighty-one million, five hundred sixty thousand, five hundred sixty-nine".