623555813 has 4 divisors (see below), whose sum is σ = 656374560. Its totient is φ = 590737068.

The previous prime is 623555749. The next prime is 623555873. The reversal of 623555813 is 318555326.

623555813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 318555326 = 2 ⋅159277663.

It is a cyclic number.

It is not a de Polignac number, because 623555813 - 2⁶ = 623555749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623555873) 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, 16409345 + ... + 16409382.

It is an arithmetic number, because the mean of its divisors is an integer number (164093640).

Almost surely, 2^623555813 is an apocalyptic number.

It is an amenable number.

623555813 is a deficient number, since it is larger than the sum of its proper divisors (32818747).

623555813 is a wasteful number, since it uses less digits than its factorization.

623555813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32818746.

The product of its digits is 108000, while the sum is 38.

The square root of 623555813 is about 24971.0995552859. The cubic root of 623555813 is about 854.3289254482.

The spelling of 623555813 in words is "six hundred twenty-three million, five hundred fifty-five thousand, eight hundred thirteen".