78440357 has 2 divisors, whose sum is σ = 78440358. Its totient is φ = 78440356.

The previous prime is 78440291. The next prime is 78440381. The reversal of 78440357 is 75304487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52287361 + 26152996 = 7231^2 + 5114^2 .

It is a cyclic number.

It is not a de Polignac number, because 78440357 - 2⁸ = 78440101 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78440357.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78440657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39220178 + 39220179.

It is an arithmetic number, because the mean of its divisors is an integer number (39220179).

Almost surely, 2^78440357 is an apocalyptic number.

It is an amenable number.

78440357 is a deficient number, since it is larger than the sum of its proper divisors (1).

78440357 is an equidigital number, since it uses as much as digits as its factorization.

78440357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94080, while the sum is 38.

The square root of 78440357 is about 8856.6560845502. The cubic root of 78440357 is about 428.0684175280.

The spelling of 78440357 in words is "seventy-eight million, four hundred forty thousand, three hundred fifty-seven".