400780 has 24 divisors (see below), whose sum is σ = 871920. Its totient is φ = 154560.

The previous prime is 400759. The next prime is 400823. The reversal of 400780 is 87004.

It is a happy number.

It is an Ulam number.

It is an unprimeable number.

400780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235 + ... + 925.

It is an arithmetic number, because the mean of its divisors is an integer number (36330).

2⁴⁰⁰⁷⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435960).

400780 is an abundant number, since it is smaller than the sum of its proper divisors (471140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400780 is a wasteful number, since it uses less digits than its factorization.

400780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729 (or 727 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 400780 is about 633.0718758561. The cubic root of 400780 is about 73.7284912859.

Adding to 400780 its reverse (87004), we get a palindrome (487784).

The spelling of 400780 in words is "four hundred thousand, seven hundred eighty".