1000405 has 16 divisors (see below), whose sum is σ = 1390464. Its totient is φ = 676800.

The previous prime is 1000403. The next prime is 1000409. The reversal of 1000405 is 5040001.

1000405 is a nontrivial binomial coefficient, being equal to C(1415, 2).

It is not a de Polignac number, because 1000405 - 2¹ = 1000403 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1000391 and 1000400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000403) 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, 3394 + ... + 3676.

It is an arithmetic number, because the mean of its divisors is an integer number (86904).

2^1000405 is an apocalyptic number.

1000405 is the 1414-th triangular number.

1000405 is the 472-nd centered nonagonal number.

It is an amenable number.

1000405 is a deficient number, since it is larger than the sum of its proper divisors (390059).

1000405 is a wasteful number, since it uses less digits than its factorization.

1000405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396.

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

The square root of 1000405 is about 1000.2024795010. The cubic root of 1000405 is about 100.0134981779.

Adding to 1000405 its reverse (5040001), we get a palindrome (6040406).

The spelling of 1000405 in words is "one million, four hundred five", and thus it is an aban number.