40208640 has 144 divisors (see below), whose sum is σ = 132353088. Its totient is φ = 10395648.

The previous prime is 40208593. The next prime is 40208647. The reversal of 40208640 is 4680204.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 40208640.

It is not an unprimeable number, because it can be changed into a prime (40208647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141939 + ... + 142221.

Almost surely, 2^40208640 is an apocalyptic number.

40208640 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 40208640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66176544).

40208640 is an abundant number, since it is smaller than the sum of its proper divisors (92144448).

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

40208640 is a wasteful number, since it uses less digits than its factorization.

40208640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 330 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 40208640 is about 6341.0283077747. The cubic root of 40208640 is about 342.5887741183.

Adding to 40208640 its reverse (4680204), we get a palindrome (44888844).

The spelling of 40208640 in words is "forty million, two hundred eight thousand, six hundred forty".