4001565 has 16 divisors (see below), whose sum is σ = 6624000. Its totient is φ = 2060352.

The previous prime is 4001561. The next prime is 4001567. The reversal of 4001565 is 5651004.

It is a happy number.

It is not a de Polignac number, because 4001565 - 2² = 4001561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4165 + ... + 5034.

It is an arithmetic number, because the mean of its divisors is an integer number (414000).

Almost surely, 2^4001565 is an apocalyptic number.

It is an amenable number.

4001565 is a deficient number, since it is larger than the sum of its proper divisors (2622435).

4001565 is a wasteful number, since it uses less digits than its factorization.

4001565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9236.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 4001565 is about 2000.3912117383. The cubic root of 4001565 is about 158.7608048529.

Adding to 4001565 its reverse (5651004), we get a palindrome (9652569).

The spelling of 4001565 in words is "four million, one thousand, five hundred sixty-five".