78286905 has 20 divisors (see below), whose sum is σ = 140337252. Its totient is φ = 41752800.

The previous prime is 78286891. The next prime is 78286909. The reversal of 78286905 is 50968287.

It can be written as a sum of positive squares in 2 ways, for example, as 10323369 + 67963536 = 3213^2 + 8244^2 .

It is not a de Polignac number, because 78286905 - 2⁶ = 78286841 is a prime.

It is a super-2 number, since 2×78286905² = 12257678988958050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (78286909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 96246 + ... + 97055.

Almost surely, 2^78286905 is an apocalyptic number.

It is an amenable number.

78286905 is a deficient number, since it is larger than the sum of its proper divisors (62050347).

78286905 is a wasteful number, since it uses less digits than its factorization.

78286905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193318 (or 193309 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 78286905 is about 8847.9887545136. The cubic root of 78286905 is about 427.7890934708.

The spelling of 78286905 in words is "seventy-eight million, two hundred eighty-six thousand, nine hundred five".