1565661223 has 16 divisors (see below), whose sum is σ = 1900252224. Its totient is φ = 1259274240.

The previous prime is 1565661203. The next prime is 1565661233. The reversal of 1565661223 is 3221665651.

It is not a de Polignac number, because 1565661223 - 2⁵ = 1565661191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565661203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20583 + ... + 59623.

It is an arithmetic number, because the mean of its divisors is an integer number (118765764).

Almost surely, 2^1565661223 is an apocalyptic number.

1565661223 is a deficient number, since it is larger than the sum of its proper divisors (334591001).

1565661223 is a wasteful number, since it uses less digits than its factorization.

1565661223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39402.

The product of its digits is 64800, while the sum is 37.

The square root of 1565661223 is about 39568.4372069456. The cubic root of 1565661223 is about 1161.1792464316.

The spelling of 1565661223 in words is "one billion, five hundred sixty-five million, six hundred sixty-one thousand, two hundred twenty-three".