623255561 has 4 divisors (see below), whose sum is σ = 623326212. Its totient is φ = 623184912.

The previous prime is 623255543. The next prime is 623255573. The reversal of 623255561 is 165552326.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 175721536 + 447534025 = 13256^2 + 21155^2 .

It is a cyclic number.

It is not a de Polignac number, because 623255561 - 2⁶ = 623255497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (623255261) 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, 19826 + ... + 40491.

It is an arithmetic number, because the mean of its divisors is an integer number (155831553).

Almost surely, 2^623255561 is an apocalyptic number.

It is an amenable number.

623255561 is a deficient number, since it is larger than the sum of its proper divisors (70651).

623255561 is a wasteful number, since it uses less digits than its factorization.

623255561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70650.

The product of its digits is 54000, while the sum is 35.

The square root of 623255561 is about 24965.0868414272. The cubic root of 623255561 is about 854.1917791303.

The spelling of 623255561 in words is "six hundred twenty-three million, two hundred fifty-five thousand, five hundred sixty-one".