400203540 has 144 divisors (see below), whose sum is σ = 1337394240. Its totient is φ = 96061440.

The previous prime is 400203539. The next prime is 400203553. The reversal of 400203540 is 45302004.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 210916 + ... + 212804.

It is an arithmetic number, because the mean of its divisors is an integer number (9287460).

Almost surely, 2^400203540 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 400203540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (668697120).

400203540 is an abundant number, since it is smaller than the sum of its proper divisors (937190700).

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

400203540 is a wasteful number, since it uses less digits than its factorization.

400203540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022 (or 2017 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 18.

The square root of 400203540 is about 20005.0878528438. The cubic root of 400203540 is about 736.9312531648.

Adding to 400203540 its reverse (45302004), we get a palindrome (445505544).

The spelling of 400203540 in words is "four hundred million, two hundred three thousand, five hundred forty".