400204240 has 20 divisors (see below), whose sum is σ = 930475044. Its totient is φ = 160081664.

The previous prime is 400204237. The next prime is 400204243. The reversal of 400204240 is 42402004.

It is an interprime number because it is at equal distance from previous prime (400204237) and next prime (400204243).

It can be written as a sum of positive squares in 2 ways, for example, as 130325056 + 269879184 = 11416^2 + 16428^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400204243) 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, 2501197 + ... + 2501356.

Almost surely, 2^400204240 is an apocalyptic number.

400204240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400204240 is an abundant number, since it is smaller than the sum of its proper divisors (530270804).

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

400204240 is a wasteful number, since it uses less digits than its factorization.

400204240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5002566 (or 5002560 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 400204240 is about 20005.1053483854. The cubic root of 400204240 is about 736.9316828225.

Adding to 400204240 its reverse (42402004), we get a palindrome (442606244).

The spelling of 400204240 in words is "four hundred million, two hundred four thousand, two hundred forty".