128840377 has 4 divisors (see below), whose sum is σ = 129067380. Its totient is φ = 128613376.

The previous prime is 128840353. The next prime is 128840419. The reversal of 128840377 is 773048821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 773048821 = 7411 ⋅104311.

It can be written as a sum of positive squares in 2 ways, for example, as 77158656 + 51681721 = 8784^2 + 7189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128840377 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 not an unprimeable number, because it can be changed into a prime (128840077) 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, 112648 + ... + 113785.

It is an arithmetic number, because the mean of its divisors is an integer number (32266845).

Almost surely, 2^128840377 is an apocalyptic number.

It is an amenable number.

128840377 is a deficient number, since it is larger than the sum of its proper divisors (227003).

128840377 is an equidigital number, since it uses as much as digits as its factorization.

128840377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227002.

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

The square root of 128840377 is about 11350.7875057196. The cubic root of 128840377 is about 505.0689406910.

The spelling of 128840377 in words is "one hundred twenty-eight million, eight hundred forty thousand, three hundred seventy-seven".