400428 has 54 divisors (see below), whose sum is σ = 1182636. Its totient is φ = 113904.

The previous prime is 400417. The next prime is 400429. The reversal of 400428 is 824004.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 400428.

It is not an unprimeable number, because it can be changed into a prime (400429) by changing a digit.

400428 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 17 ways as a sum of consecutive naturals, for example, 1651 + ... + 1877.

2⁴⁰⁰⁴²⁸ 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 400428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (591318).

400428 is an abundant number, since it is smaller than the sum of its proper divisors (782208).

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

400428 is a wasteful number, since it uses less digits than its factorization.

400428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 400428 is about 632.7938052794. The cubic root of 400428 is about 73.7069000301.

It can be divided in two parts, 400 and 428, that added together give a palindrome (828).

The spelling of 400428 in words is "four hundred thousand, four hundred twenty-eight".