78720285 has 32 divisors (see below), whose sum is σ = 152416512. Its totient is φ = 33868800.

The previous prime is 78720281. The next prime is 78720289. The reversal of 78720285 is 58202787.

It is an interprime number because it is at equal distance from previous prime (78720281) and next prime (78720289).

It is not a de Polignac number, because 78720285 - 2² = 78720281 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78720281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20266 + ... + 23835.

It is an arithmetic number, because the mean of its divisors is an integer number (4763016).

Almost surely, 2^78720285 is an apocalyptic number.

It is an amenable number.

78720285 is a deficient number, since it is larger than the sum of its proper divisors (73696227).

78720285 is a wasteful number, since it uses less digits than its factorization.

78720285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44133.

The product of its (nonzero) digits is 62720, while the sum is 39.

The square root of 78720285 is about 8872.4452661034. The cubic root of 78720285 is about 428.5770250856.

The spelling of 78720285 in words is "seventy-eight million, seven hundred twenty thousand, two hundred eighty-five".