401815 has 4 divisors (see below), whose sum is σ = 482184. Its totient is φ = 321448.

The previous prime is 401813. The next prime is 401827. The reversal of 401815 is 518104.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 401815 - 2¹ = 401813 is a prime.

It is a super-2 number, since 2×401815² = 322910588450, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 401792 and 401801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40177 + ... + 40186.

It is an arithmetic number, because the mean of its divisors is an integer number (120546).

2⁴⁰¹⁸¹⁵ is an apocalyptic number.

401815 is a deficient number, since it is larger than the sum of its proper divisors (80369).

401815 is an equidigital number, since it uses as much as digits as its factorization.

401815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80368.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 401815 is about 633.8887915084. Note that the first 3 decimals coincide. The cubic root of 401815 is about 73.7919037933.

Adding to 401815 its reverse (518104), we get a palindrome (919919).

It can be divided in two parts, 40181 and 5, that added together give a triangular number (40186 = T₂₈₃).

The spelling of 401815 in words is "four hundred one thousand, eight hundred fifteen".