1645222565 has 16 divisors (see below), whose sum is σ = 2277010560. Its totient is φ = 1117800000.

The previous prime is 1645222547. The next prime is 1645222567. The reversal of 1645222565 is 5652225461.

It is a happy number.

It is not a de Polignac number, because 1645222565 - 2⁸ = 1645222309 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645222567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211811 + ... + 219440.

It is an arithmetic number, because the mean of its divisors is an integer number (142313160).

Almost surely, 2^1645222565 is an apocalyptic number.

It is an amenable number.

1645222565 is a deficient number, since it is larger than the sum of its proper divisors (631787995).

1645222565 is a wasteful number, since it uses less digits than its factorization.

1645222565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431372.

The product of its digits is 144000, while the sum is 38.

The square root of 1645222565 is about 40561.3432346613. The cubic root of 1645222565 is about 1180.5241770086.

The spelling of 1645222565 in words is "one billion, six hundred forty-five million, two hundred twenty-two thousand, five hundred sixty-five".