128940040 has 16 divisors (see below), whose sum is σ = 290115180. Its totient is φ = 51576000.

The previous prime is 128940017. The next prime is 128940059. The reversal of 128940040 is 40049821.

It can be written as a sum of positive squares in 2 ways, for example, as 125933284 + 3006756 = 11222^2 + 1734^2 .

It is a junction number, because it is equal to n+sod(n) for n = 128939990 and 128940008.

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, 1611711 + ... + 1611790.

Almost surely, 2^128940040 is an apocalyptic number.

128940040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128940040 is an abundant number, since it is smaller than the sum of its proper divisors (161175140).

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

128940040 is a wasteful number, since it uses less digits than its factorization.

128940040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3223512 (or 3223508 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 128940040 is about 11355.1767929874. The cubic root of 128940040 is about 505.1991372268.

Adding to 128940040 its reverse (40049821), we get a palindrome (168989861).

The spelling of 128940040 in words is "one hundred twenty-eight million, nine hundred forty thousand, forty".