78767609 has 2 divisors, whose sum is σ = 78767610. Its totient is φ = 78767608.

The previous prime is 78767603. The next prime is 78767639. The reversal of 78767609 is 90676787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78712384 + 55225 = 8872^2 + 235^2 .

It is a cyclic number.

It is not a de Polignac number, because 78767609 - 2¹² = 78763513 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78767603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39383804 + 39383805.

It is an arithmetic number, because the mean of its divisors is an integer number (39383805).

Almost surely, 2^78767609 is an apocalyptic number.

It is an amenable number.

78767609 is a deficient number, since it is larger than the sum of its proper divisors (1).

78767609 is an equidigital number, since it uses as much as digits as its factorization.

78767609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 889056, while the sum is 50.

The square root of 78767609 is about 8875.1117739440. Note that the first 3 decimals coincide. The cubic root of 78767609 is about 428.6628899349.

The spelling of 78767609 in words is "seventy-eight million, seven hundred sixty-seven thousand, six hundred nine".