40181840 has 40 divisors (see below), whose sum is σ = 94366728. Its totient is φ = 15910400.

The previous prime is 40181831. The next prime is 40181861. The reversal of 40181840 is 4818104.

It can be written as a sum of positive squares in 4 ways, for example, as 16289296 + 23892544 = 4036^2 + 4888^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×40181840² = 3229160531571200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5594 + ... + 10566.

Almost surely, 2^40181840 is an apocalyptic number.

40181840 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 40181840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47183364).

40181840 is an abundant number, since it is smaller than the sum of its proper divisors (54184888).

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

40181840 is a wasteful number, since it uses less digits than its factorization.

40181840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5087 (or 5081 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 40181840 is about 6338.9147336117. The cubic root of 40181840 is about 342.5126427215.

Adding to 40181840 its reverse (4818104), we get a palindrome (44999944).

The spelling of 40181840 in words is "forty million, one hundred eighty-one thousand, eight hundred forty".