401005 has 16 divisors (see below), whose sum is σ = 549504. Its totient is φ = 278080.

The previous prime is 400997. The next prime is 401017. The reversal of 401005 is 500104.

401005 = T₃₉₈ + T₃₉₉ + ... + T₄₀₂.

It is not a de Polignac number, because 401005 - 2³ = 400997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400982 and 401000.

It is a congruent number.

It is an unprimeable number.

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, 1107 + ... + 1423.

It is an arithmetic number, because the mean of its divisors is an integer number (34344).

2⁴⁰¹⁰⁰⁵ is an apocalyptic number.

401005 is the 317-th decagonal number.

It is an amenable number.

401005 is a deficient number, since it is larger than the sum of its proper divisors (148499).

401005 is a wasteful number, since it uses less digits than its factorization.

401005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 401005 is about 633.2495558625. The cubic root of 401005 is about 73.7422858924.

Adding to 401005 its reverse (500104), we get a palindrome (901109).

Subtracting 401005 from its reverse (500104), we obtain a palindrome (99099).

The spelling of 401005 in words is "four hundred one thousand, five".