400687 has 4 divisors (see below), whose sum is σ = 457936. Its totient is φ = 343440.

The previous prime is 400681. The next prime is 400703. The reversal of 400687 is 786004.

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 400687 - 2³ = 400679 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400681) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 28614 + ... + 28627.

It is an arithmetic number, because the mean of its divisors is an integer number (114484).

2⁴⁰⁰⁶⁸⁷ is an apocalyptic number.

400687 is a deficient number, since it is larger than the sum of its proper divisors (57249).

400687 is an equidigital number, since it uses as much as digits as its factorization.

400687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57248.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 400687 is about 632.9984202192. The cubic root of 400687 is about 73.7227880072.

The spelling of 400687 in words is "four hundred thousand, six hundred eighty-seven".