623655209 has 4 divisors (see below), whose sum is σ = 624011520. Its totient is φ = 623298900.

The previous prime is 623655199. The next prime is 623655269. The reversal of 623655209 is 902556326.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-623655209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (623655269) 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, 175517 + ... + 179034.

It is an arithmetic number, because the mean of its divisors is an integer number (156002880).

Almost surely, 2^623655209 is an apocalyptic number.

It is an amenable number.

623655209 is a deficient number, since it is larger than the sum of its proper divisors (356311).

623655209 is a wasteful number, since it uses less digits than its factorization.

623655209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356310.

The product of its (nonzero) digits is 97200, while the sum is 38.

The square root of 623655209 is about 24973.0896967115. The cubic root of 623655209 is about 854.3743169297.

The spelling of 623655209 in words is "six hundred twenty-three million, six hundred fifty-five thousand, two hundred nine".