400081 has 8 divisors (see below), whose sum is σ = 448704. Its totient is φ = 353520.

The previous prime is 400069. The next prime is 400087. The reversal of 400081 is 180004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400081 - 2⁷ = 399953 is a prime.

It is a super-2 number, since 2×400081² = 320129613122, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

400081 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85 + ... + 898.

It is an arithmetic number, because the mean of its divisors is an integer number (56088).

2⁴⁰⁰⁰⁸¹ is an apocalyptic number.

It is an amenable number.

400081 is a deficient number, since it is larger than the sum of its proper divisors (48623).

400081 is a wasteful number, since it uses less digits than its factorization.

400081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 400081 is about 632.5195649148. The cubic root of 400081 is about 73.6856030797.

Adding to 400081 its reverse (180004), we get a palindrome (580085).

The spelling of 400081 in words is "four hundred thousand, eighty-one".