40181821840 has 40 divisors (see below), whose sum is σ = 93690487800. Its totient is φ = 16026663936.

The previous prime is 40181821789. The next prime is 40181821861. The reversal of 40181821840 is 4812818104.

It can be written as a sum of positive squares in 4 ways, for example, as 352838656 + 39828983184 = 18784^2 + 199572^2 .

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

It is a super-2 number, since 2×40181821840² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 40181821840.

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, 691669 + ... + 747508.

It is an arithmetic number, because the mean of its divisors is an integer number (2342262195).

Almost surely, 2^40181821840 is an apocalyptic number.

40181821840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40181821840 is an abundant number, since it is smaller than the sum of its proper divisors (53508665960).

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

40181821840 is a wasteful number, since it uses less digits than its factorization.

40181821840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439539 (or 1439533 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 37.

The spelling of 40181821840 in words is "forty billion, one hundred eighty-one million, eight hundred twenty-one thousand, eight hundred forty".