40000040 has 32 divisors (see below), whose sum is σ = 90900360. Its totient is φ = 15840000.

The previous prime is 40000033. The next prime is 40000061. The reversal of 40000040 is 4000004.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39413284 + 586756 = 6278^2 + 766^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a junction number, because it is equal to n+sod(n) for n = 39999982 and 40000027.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 911 + ... + 8990.

Almost surely, 2^40000040 is an apocalyptic number.

40000040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40000040 is an abundant number, since it is smaller than the sum of its proper divisors (50900320).

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

40000040 is a wasteful number, since it uses less digits than its factorization.

40000040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10013 (or 10009 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 8.

The square root of 40000040 is about 6324.5584826136. The cubic root of 40000040 is about 341.9953033337.

Adding to 40000040 its reverse (4000004), we get a palindrome (44000044).

It can be divided in two parts, 400000 and 40, that multiplied together give a square (16000000 = 4000²).

The spelling of 40000040 in words is "forty million, forty", and thus it is an aban number, an eban number, and an uban number.