40408240 has 40 divisors (see below), whose sum is σ = 98038368. Its totient is φ = 15459840.

The previous prime is 40408237. The next prime is 40408241. The reversal of 40408240 is 4280404.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (40408241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9141 + ... + 12820.

Almost surely, 2^40408240 is an apocalyptic number.

40408240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40408240 is an abundant number, since it is smaller than the sum of its proper divisors (57630128).

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

40408240 is a wasteful number, since it uses less digits than its factorization.

40408240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21997 (or 21991 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

The square root of 40408240 is about 6356.7475960589. The cubic root of 40408240 is about 343.1547211435.

Adding to 40408240 its reverse (4280404), we get a palindrome (44688644).

The spelling of 40408240 in words is "forty million, four hundred eight thousand, two hundred forty".