406781 has 4 divisors (see below), whose sum is σ = 410112. Its totient is φ = 403452.

The previous prime is 406739. The next prime is 406789. The reversal of 406781 is 187604.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 406781 - 2⁶ = 406717 is a prime.

It is a super-2 number, since 2×406781² = 330941563922, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 406781.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 406781.

It is not an unprimeable number, because it can be changed into a prime (406789) 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, 1475 + ... + 1728.

It is an arithmetic number, because the mean of its divisors is an integer number (102528).

2⁴⁰⁶⁷⁸¹ is an apocalyptic number.

It is an amenable number.

406781 is a deficient number, since it is larger than the sum of its proper divisors (3331).

406781 is a wasteful number, since it uses less digits than its factorization.

406781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3330.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 406781 is about 637.7938538431. The cubic root of 406781 is about 74.0946560800.

The spelling of 406781 in words is "four hundred six thousand, seven hundred eighty-one".