40320640 has 48 divisors (see below), whose sum is σ = 96777090. Its totient is φ = 16064000.

The previous prime is 40320629. The next prime is 40320661. The reversal of 40320640 is 4602304.

It can be written as a sum of positive squares in only one way, i.e., 36288576 + 4032064 = 6024^2 + 2008^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 160515 + ... + 160765.

Almost surely, 2^40320640 is an apocalyptic number.

40320640 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 40320640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48388545).

40320640 is an abundant number, since it is smaller than the sum of its proper divisors (56456450).

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

40320640 is an frugal number, since it uses more digits than its factorization.

40320640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 40320640 is about 6349.8535416181. The cubic root of 40320640 is about 342.9065695938.

Adding to 40320640 its reverse (4602304), we get a palindrome (44922944).

The spelling of 40320640 in words is "forty million, three hundred twenty thousand, six hundred forty".