401565 has 16 divisors (see below), whose sum is σ = 676800. Its totient is φ = 202752.

The previous prime is 401551. The next prime is 401567. The reversal of 401565 is 565104.

It is a happy number.

It is not a de Polignac number, because 401565 - 2⁸ = 401309 is a prime.

It is a super-2 number, since 2×401565² = 322508898450, which contains 22 as substring.

401565 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401567) 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, 420 + ... + 989.

It is an arithmetic number, because the mean of its divisors is an integer number (42300).

2⁴⁰¹⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

401565 is a deficient number, since it is larger than the sum of its proper divisors (275235).

401565 is a wasteful number, since it uses less digits than its factorization.

401565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436.

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

The square root of 401565 is about 633.6915653534. The cubic root of 401565 is about 73.7765967463.

Adding to 401565 its reverse (565104), we get a palindrome (966669).

The spelling of 401565 in words is "four hundred one thousand, five hundred sixty-five".