42543440 has 20 divisors (see below), whose sum is σ = 98913684. Its totient is φ = 17017344.

The previous prime is 42543433. The next prime is 42543443. The reversal of 42543440 is 4434524.

42543440 = 24² + 25² + ... + 503².

It can be written as a sum of positive squares in 2 ways, for example, as 4892944 + 37650496 = 2212^2 + 6136^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42543443) 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, 265817 + ... + 265976.

Almost surely, 2^42543440 is an apocalyptic number.

42543440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42543440 is an abundant number, since it is smaller than the sum of its proper divisors (56370244).

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

42543440 is a wasteful number, since it uses less digits than its factorization.

42543440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531806 (or 531800 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 26.

The square root of 42543440 is about 6522.5332502027. The cubic root of 42543440 is about 349.0954602403.

Adding to 42543440 its reverse (4434524), we get a palindrome (46977964).

The spelling of 42543440 in words is "forty-two million, five hundred forty-three thousand, four hundred forty".