40408040 has 16 divisors (see below), whose sum is σ = 90918180. Its totient is φ = 16163200.

The previous prime is 40408021. The next prime is 40408057. The reversal of 40408040 is 4080404.

It can be written as a sum of positive squares in 2 ways, for example, as 38464804 + 1943236 = 6202^2 + 1394^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505061 + ... + 505140.

Almost surely, 2^40408040 is an apocalyptic number.

40408040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40408040 is an abundant number, since it is smaller than the sum of its proper divisors (50510140).

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

40408040 is a wasteful number, since it uses less digits than its factorization.

40408040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010212 (or 1010208 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 40408040 is about 6356.7318647242. The cubic root of 40408040 is about 343.1541549961.

Adding to 40408040 its reverse (4080404), we get a palindrome (44488444).

It can be divided in two parts, 40 and 408040, that multiplied together give a square (16321600 = 4040²).

The spelling of 40408040 in words is "forty million, four hundred eight thousand, forty".