1643226565 has 8 divisors (see below), whose sum is σ = 2039867640. Its totient is φ = 1269250752.

The previous prime is 1643226551. The next prime is 1643226583. The reversal of 1643226565 is 5656223461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 22600516 + 1620626049 = 4754^2 + 40257^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1643226565 - 2⁷ = 1643226437 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5666154 + ... + 5666443.

It is an arithmetic number, because the mean of its divisors is an integer number (254983455).

Almost surely, 2^1643226565 is an apocalyptic number.

It is an amenable number.

1643226565 is a deficient number, since it is larger than the sum of its proper divisors (396641075).

1643226565 is a wasteful number, since it uses less digits than its factorization.

1643226565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11332631.

The product of its digits is 259200, while the sum is 40.

The square root of 1643226565 is about 40536.7310596205. The cubic root of 1643226565 is about 1180.0465760128.

The spelling of 1643226565 in words is "one billion, six hundred forty-three million, two hundred twenty-six thousand, five hundred sixty-five".