1561223565 has 40 divisors (see below), whose sum is σ = 3053068128. Its totient is φ = 756954720.

The previous prime is 1561223563. The next prime is 1561223567. The reversal of 1561223565 is 5653221651.

1561223565 is a `hidden beast` number, since 1 + 5 + 612 + 2 + 35 + 6 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1561223563) and next prime (1561223567).

It is not a de Polignac number, because 1561223565 - 2¹ = 1561223563 is a prime.

It is a super-2 number, since 2×1561223565² = 4874838039822618450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561223561) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 170767 + ... + 179676.

Almost surely, 2^1561223565 is an apocalyptic number.

1561223565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561223565 is a deficient number, since it is larger than the sum of its proper divisors (1491844563).

1561223565 is a wasteful number, since it uses less digits than its factorization.

1561223565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350471 (or 350462 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 1561223565 is about 39512.3216857729. The cubic root of 1561223565 is about 1160.0811390430.

The spelling of 1561223565 in words is "one billion, five hundred sixty-one million, two hundred twenty-three thousand, five hundred sixty-five".