78833561 has 2 divisors, whose sum is σ = 78833562. Its totient is φ = 78833560.

The previous prime is 78833551. The next prime is 78833563. The reversal of 78833561 is 16533887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69622336 + 9211225 = 8344^2 + 3035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78833561 is a prime.

It is a Sophie Germain prime.

Together with 78833563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78833563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39416780 + 39416781.

It is an arithmetic number, because the mean of its divisors is an integer number (39416781).

Almost surely, 2^78833561 is an apocalyptic number.

It is an amenable number.

78833561 is a deficient number, since it is larger than the sum of its proper divisors (1).

78833561 is an equidigital number, since it uses as much as digits as its factorization.

78833561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 41.

The square root of 78833561 is about 8878.8265553507. The cubic root of 78833561 is about 428.7824961557.

The spelling of 78833561 in words is "seventy-eight million, eight hundred thirty-three thousand, five hundred sixty-one".