40209988 has 72 divisors (see below), whose sum is σ = 90448512. Its totient is φ = 15494976.

The previous prime is 40209943. The next prime is 40209989. The reversal of 40209988 is 88990204.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 40209988.

It is not an unprimeable number, because it can be changed into a prime (40209989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109381 + ... + 109747.

Almost surely, 2^40209988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40209988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45224256).

40209988 is an abundant number, since it is smaller than the sum of its proper divisors (50238524).

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

40209988 is a wasteful number, since it uses less digits than its factorization.

40209988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 432 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 40209988 is about 6341.1345987922. The cubic root of 40209988 is about 342.5926025202.

The spelling of 40209988 in words is "forty million, two hundred nine thousand, nine hundred eighty-eight".