128738440 has 32 divisors (see below), whose sum is σ = 290171160. Its totient is φ = 51404800.

The previous prime is 128738417. The next prime is 128738543. The reversal of 128738440 is 44837821.

It can be written as a sum of positive squares in 4 ways, for example, as 128731716 + 6724 = 11346^2 + 82^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 128738440.

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, 23130 + ... + 28150.

Almost surely, 2^128738440 is an apocalyptic number.

128738440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128738440 is an abundant number, since it is smaller than the sum of its proper divisors (161432720).

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

128738440 is a wasteful number, since it uses less digits than its factorization.

128738440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5673 (or 5669 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 37.

The square root of 128738440 is about 11346.2963120130. The cubic root of 128738440 is about 504.9357039993.

The spelling of 128738440 in words is "one hundred twenty-eight million, seven hundred thirty-eight thousand, four hundred forty".