129000040 has 32 divisors (see below), whose sum is σ = 312578280. Its totient is φ = 47630592.

The previous prime is 129000037. The next prime is 129000049. The reversal of 129000040 is 40000921.

It can be written as a sum of positive squares in 4 ways, for example, as 100761444 + 28238596 = 10038^2 + 5314^2 .

It is a junction number, because it is equal to n+sod(n) for n = 128999978 and 129000023.

It is not an unprimeable number, because it can be changed into a prime (129000049) 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, 123519 + ... + 124558.

Almost surely, 2^129000040 is an apocalyptic number.

129000040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129000040 is an abundant number, since it is smaller than the sum of its proper divisors (183578240).

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

129000040 is a wasteful number, since it uses less digits than its factorization.

129000040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248101 (or 248097 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 129000040 is about 11357.8184525022. The cubic root of 129000040 is about 505.2774869459.

Adding to 129000040 its reverse (40000921), we get a palindrome (169000961).

The spelling of 129000040 in words is "one hundred twenty-nine million, forty", and thus it is an aban number.