80705561 has 2 divisors, whose sum is σ = 80705562. Its totient is φ = 80705560.

The previous prime is 80705543. The next prime is 80705609. The reversal of 80705561 is 16550708.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66113161 + 14592400 = 8131^2 + 3820^2 .

It is a cyclic number.

It is not a de Polignac number, because 80705561 - 2⁶ = 80705497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (80705761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40352780 + 40352781.

It is an arithmetic number, because the mean of its divisors is an integer number (40352781).

Almost surely, 2^80705561 is an apocalyptic number.

It is an amenable number.

80705561 is a deficient number, since it is larger than the sum of its proper divisors (1).

80705561 is an equidigital number, since it uses as much as digits as its factorization.

80705561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 80705561 is about 8983.6273854162. The cubic root of 80705561 is about 432.1499697224.

It can be divided in two parts, 8070 and 5561, that added together give a palindrome (13631).

The spelling of 80705561 in words is "eighty million, seven hundred five thousand, five hundred sixty-one".