42404240 has 80 divisors (see below), whose sum is σ = 102569328. Its totient is φ = 16293888.

The previous prime is 42404231. The next prime is 42404251. The reversal of 42404240 is 4240424.

It can be written as a sum of positive squares in 8 ways, for example, as 620944 + 41783296 = 788^2 + 6464^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 309452 + ... + 309588.

Almost surely, 2^42404240 is an apocalyptic number.

42404240 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 42404240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51284664).

42404240 is an abundant number, since it is smaller than the sum of its proper divisors (60165088).

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

42404240 is a wasteful number, since it uses less digits than its factorization.

42404240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

The square root of 42404240 is about 6511.8538067128. The cubic root of 42404240 is about 348.7143032883.

42404240 divided by its sum of digits (20) gives a palindrome (2120212).

Adding to 42404240 its reverse (4240424), we get a palindrome (46644664).

The spelling of 42404240 in words is "forty-two million, four hundred four thousand, two hundred forty".