42040040 has 96 divisors (see below), whose sum is σ = 111731400. Its totient is φ = 14192640.

The previous prime is 42040007. The next prime is 42040051. The reversal of 42040040 is 4004024.

42040040 = T₃₈₁ + T₃₈₂ + ... + T₆₇₄.

It can be written as a sum of positive squares in 4 ways, for example, as 32467204 + 9572836 = 5698^2 + 3094^2 .

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 42039997 and 42040024.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 174320 + ... + 174560.

Almost surely, 2^42040040 is an apocalyptic number.

42040040 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 42040040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55865700).

42040040 is an abundant number, since it is smaller than the sum of its proper divisors (69691360).

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

42040040 is a wasteful number, since it uses less digits than its factorization.

42040040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 42040040 is about 6483.8291155767. The cubic root of 42040040 is about 347.7130898076.

Adding to 42040040 its reverse (4004024), we get a palindrome (46044064).

The spelling of 42040040 in words is "forty-two million, forty thousand, forty", and thus it is an eban number.