646078 has 8 divisors (see below), whose sum is σ = 992880. Its totient is φ = 315120.

The previous prime is 646073. The next prime is 646099. The reversal of 646078 is 870646.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646073) by changing a digit.

646078 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3858 + ... + 4021.

It is an arithmetic number, because the mean of its divisors is an integer number (124110).

2⁶⁴⁶⁰⁷⁸ is an apocalyptic number.

646078 is a deficient number, since it is larger than the sum of its proper divisors (346802).

646078 is a wasteful number, since it uses less digits than its factorization.

646078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7922.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 646078 is about 803.7897735105. The cubic root of 646078 is about 86.4493338224.

The spelling of 646078 in words is "six hundred forty-six thousand, seventy-eight".