128408737 has 4 divisors (see below), whose sum is σ = 129060756. Its totient is φ = 127756720.

The previous prime is 128408729. The next prime is 128408767. The reversal of 128408737 is 737804821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 105760656 + 22648081 = 10284^2 + 4759^2 .

It is a cyclic number.

It is not a de Polignac number, because 128408737 - 2³ = 128408729 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128408737.

It is not an unprimeable number, because it can be changed into a prime (128408717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 325714 + ... + 326107.

It is an arithmetic number, because the mean of its divisors is an integer number (32265189).

Almost surely, 2^128408737 is an apocalyptic number.

It is an amenable number.

128408737 is a deficient number, since it is larger than the sum of its proper divisors (652019).

128408737 is an equidigital number, since it uses as much as digits as its factorization.

128408737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652018.

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 128408737 is about 11331.7578954018. The cubic root of 128408737 is about 504.5042836765.

The spelling of 128408737 in words is "one hundred twenty-eight million, four hundred eight thousand, seven hundred thirty-seven".