40305440 has 144 divisors (see below), whose sum is σ = 114021432. Its totient is φ = 13418496.

The previous prime is 40305409. The next prime is 40305443. The reversal of 40305440 is 4450304.

40305440 = 596² + 597² + ... + 692².

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 34904464 + 5400976 = 5908^2 + 2324^2 .

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

It is not an unprimeable number, because it can be changed into a prime (40305443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 415472 + ... + 415568.

Almost surely, 2^40305440 is an apocalyptic number.

40305440 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 40305440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57010716).

40305440 is an abundant number, since it is smaller than the sum of its proper divisors (73715992).

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

40305440 is a wasteful number, since it uses less digits than its factorization.

40305440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 40305440 is about 6348.6565507988. The cubic root of 40305440 is about 342.8634747508.

Adding to 40305440 its reverse (4450304), we get a palindrome (44755744).

The spelling of 40305440 in words is "forty million, three hundred five thousand, four hundred forty".