40644000 has 144 divisors (see below), whose sum is σ = 144373320. Its totient is φ = 10828800.

The previous prime is 40643971. The next prime is 40644001. The reversal of 40644000 is 44604.

It can be written as a sum of positive squares in 4 ways, for example, as 4210704 + 36433296 = 2052^2 + 6036^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (40644001) 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, 35436 + ... + 36564.

Almost surely, 2^40644000 is an apocalyptic number.

40644000 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 40644000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72186660).

40644000 is an abundant number, since it is smaller than the sum of its proper divisors (103729320).

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

40644000 is a wasteful number, since it uses less digits than its factorization.

40644000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1160 (or 1139 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 40644000 is about 6375.2647003870. The cubic root of 40644000 is about 343.8208008434.

Adding to 40644000 its reverse (44604), we get a palindrome (40688604).

The spelling of 40644000 in words is "forty million, six hundred forty-four thousand".