78905 has 8 divisors (see below), whose sum is σ = 97152. Its totient is φ = 61488.

The previous prime is 78901. The next prime is 78919. The reversal of 78905 is 50987.

78905 = 20² + 21² + ... + 62².

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78905 - 2² = 78901 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32 + ... + 398.

It is an arithmetic number, because the mean of its divisors is an integer number (12144).

2⁷⁸⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

78905 is a deficient number, since it is larger than the sum of its proper divisors (18247).

78905 is a wasteful number, since it uses less digits than its factorization.

78905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 78905 is about 280.9003381984. The cubic root of 78905 is about 42.8911978000.

The spelling of 78905 in words is "seventy-eight thousand, nine hundred five".