623144521 has 4 divisors (see below), whose sum is σ = 623294100. Its totient is φ = 622994944.

The previous prime is 623144513. The next prime is 623144531. The reversal of 623144521 is 125441326.

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

It can be written as a sum of positive squares in 2 ways, for example, as 289680400 + 333464121 = 17020^2 + 18261^2 .

It is a cyclic number.

It is not a de Polignac number, because 623144521 - 2³ = 623144513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 623144521.

It is not an unprimeable number, because it can be changed into a prime (623144531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68356 + ... + 76933.

It is an arithmetic number, because the mean of its divisors is an integer number (155823525).

Almost surely, 2^623144521 is an apocalyptic number.

It is an amenable number.

623144521 is a deficient number, since it is larger than the sum of its proper divisors (149579).

623144521 is a wasteful number, since it uses less digits than its factorization.

623144521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149578.

The product of its digits is 5760, while the sum is 28.

The square root of 623144521 is about 24962.8628366219. The cubic root of 623144521 is about 854.1410481544.

Adding to 623144521 its reverse (125441326), we get a palindrome (748585847).

The spelling of 623144521 in words is "six hundred twenty-three million, one hundred forty-four thousand, five hundred twenty-one".