623221509 has 4 divisors (see below), whose sum is σ = 830962016. Its totient is φ = 415481004.

The previous prime is 623221493. The next prime is 623221523. The reversal of 623221509 is 905122326.

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 not a de Polignac number, because 623221509 - 2⁴ = 623221493 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 (623221579) 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, 103870249 + ... + 103870254.

It is an arithmetic number, because the mean of its divisors is an integer number (207740504).

Almost surely, 2^623221509 is an apocalyptic number.

It is an amenable number.

623221509 is a deficient number, since it is larger than the sum of its proper divisors (207740507).

623221509 is a wasteful number, since it uses less digits than its factorization.

623221509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207740506.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 623221509 is about 24964.4048396913. The cubic root of 623221509 is about 854.1762223935.

The spelling of 623221509 in words is "six hundred twenty-three million, two hundred twenty-one thousand, five hundred nine".