78905057 has 16 divisors (see below), whose sum is σ = 100472832. Its totient is φ = 60173520.

The previous prime is 78905051. The next prime is 78905063. The reversal of 78905057 is 75050987.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78905051) and next prime (78905063).

It is not a de Polignac number, because 78905057 - 2⁶ = 78904993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78905051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7283 + ... + 14520.

It is an arithmetic number, because the mean of its divisors is an integer number (6279552).

Almost surely, 2^78905057 is an apocalyptic number.

78905057 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

It is an amenable number.

78905057 is a deficient number, since it is larger than the sum of its proper divisors (21567775).

78905057 is a wasteful number, since it uses less digits than its factorization.

78905057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21868.

The product of its (nonzero) digits is 88200, while the sum is 41.

The square root of 78905057 is about 8882.8518506164. The cubic root of 78905057 is about 428.9120812800.

The spelling of 78905057 in words is "seventy-eight million, nine hundred five thousand, fifty-seven".