646785823 has 4 divisors (see below), whose sum is σ = 650658960. Its totient is φ = 642912688.

The previous prime is 646785817. The next prime is 646785827. The reversal of 646785823 is 328587646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646785823 - 2⁹ = 646785311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646785827) 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, 1936318 + ... + 1936651.

It is an arithmetic number, because the mean of its divisors is an integer number (162664740).

Almost surely, 2^646785823 is an apocalyptic number.

646785823 is a deficient number, since it is larger than the sum of its proper divisors (3873137).

646785823 is a wasteful number, since it uses less digits than its factorization.

646785823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3873136.

The product of its digits is 1935360, while the sum is 49.

The square root of 646785823 is about 25431.9842521184. The cubic root of 646785823 is about 864.8089270235.

The spelling of 646785823 in words is "six hundred forty-six million, seven hundred eighty-five thousand, eight hundred twenty-three".