400688 has 20 divisors (see below), whose sum is σ = 788640. Its totient is φ = 197184.

The previous prime is 400681. The next prime is 400703. The reversal of 400688 is 886004.

It is a Cunningham number, because it is equal to 633²-1.

It is not an unprimeable number, because it can be changed into a prime (400681) 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, 1106 + ... + 1422.

It is an arithmetic number, because the mean of its divisors is an integer number (39432).

2⁴⁰⁰⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

400688 is a deficient number, since it is larger than the sum of its proper divisors (387952).

400688 is a wasteful number, since it uses less digits than its factorization.

400688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 400688 is about 632.9992101101. Note that the first 3 decimals coincide. The cubic root of 400688 is about 73.7228493375.

The spelling of 400688 in words is "four hundred thousand, six hundred eighty-eight".