778423 has 4 divisors (see below), whose sum is σ = 781920. Its totient is φ = 774928.

The previous prime is 778417. The next prime is 778439. The reversal of 778423 is 324877.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 324877 = 7 ⋅46411.

It is a cyclic number.

It is not a de Polignac number, because 778423 - 2⁵ = 778391 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1390 + ... + 1867.

It is an arithmetic number, because the mean of its divisors is an integer number (195480).

2⁷⁷⁸⁴²³ is an apocalyptic number.

778423 is a deficient number, since it is larger than the sum of its proper divisors (3497).

778423 is a wasteful number, since it uses less digits than its factorization.

778423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3496.

The product of its digits is 9408, while the sum is 31.

The square root of 778423 is about 882.2828344698. The cubic root of 778423 is about 91.9895624580.

The spelling of 778423 in words is "seven hundred seventy-eight thousand, four hundred twenty-three".