15621223 has 6 divisors (see below), whose sum is σ = 15827784. Its totient is φ = 15417324.

The previous prime is 15621217. The next prime is 15621239. The reversal of 15621223 is 32212651.

It is a de Polignac number, because none of the positive numbers 2^k-15621223 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15621194 and 15621203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15621293) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4990 + ... + 7492.

It is an arithmetic number, because the mean of its divisors is an integer number (2637964).

Almost surely, 2^15621223 is an apocalyptic number.

15621223 is a deficient number, since it is larger than the sum of its proper divisors (206561).

15621223 is an frugal number, since it uses more digits than its factorization.

15621223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2661 (or 2582 counting only the distinct ones).

The product of its digits is 720, while the sum is 22.

The square root of 15621223 is about 3952.3692894263. The cubic root of 15621223 is about 249.9798543767.

Adding to 15621223 its reverse (32212651), we get a palindrome (47833874).

The spelling of 15621223 in words is "fifteen million, six hundred twenty-one thousand, two hundred twenty-three".