400520 has 64 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 138240.

The previous prime is 400481. The next prime is 400523. The reversal of 400520 is 25004.

400520 = T₁₄₅ + T₁₄₆ + ... + T₁₇₅.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 400520.

It is not an unprimeable number, because it can be changed into a prime (400523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12905 + ... + 12935.

It is an arithmetic number, because the mean of its divisors is an integer number (16200).

2⁴⁰⁰⁵²⁰ is an apocalyptic number.

400520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (518400).

400520 is an abundant number, since it is smaller than the sum of its proper divisors (636280).

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

400520 is a wasteful number, since it uses less digits than its factorization.

400520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 400520 is about 632.8664946100. The cubic root of 400520 is about 73.7125444202.

Adding to 400520 its reverse (25004), we get a palindrome (425524).

The spelling of 400520 in words is "four hundred thousand, five hundred twenty".