40404240 has 120 divisors (see below), whose sum is σ = 143716248. Its totient is φ = 10137600.

The previous prime is 40404239. The next prime is 40404269. The reversal of 40404240 is 4240404.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3825936 + 36578304 = 1956^2 + 6048^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10590 + ... + 13890.

Almost surely, 2^40404240 is an apocalyptic number.

40404240 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 40404240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71858124).

40404240 is an abundant number, since it is smaller than the sum of its proper divisors (103312008).

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

40404240 is a wasteful number, since it uses less digits than its factorization.

40404240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337 (or 3328 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

The square root of 40404240 is about 6356.4329619685. The cubic root of 40404240 is about 343.1433978410.

Adding to 40404240 its reverse (4240404), we get a palindrome (44644644).

The spelling of 40404240 in words is "forty million, four hundred four thousand, two hundred forty".