128977409 has 12 divisors (see below), whose sum is σ = 143038308. Its totient is φ = 116202240.

The previous prime is 128977403. The next prime is 128977421. The reversal of 128977409 is 904779821.

It can be written as a sum of positive squares in 2 ways, for example, as 36336784 + 92640625 = 6028^2 + 9625^2 .

It is a de Polignac number, because none of the positive numbers 2^k-128977409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128977403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8957 + ... + 18389.

It is an arithmetic number, because the mean of its divisors is an integer number (11919859).

Almost surely, 2^128977409 is an apocalyptic number.

It is an amenable number.

128977409 is a deficient number, since it is larger than the sum of its proper divisors (14060899).

128977409 is a wasteful number, since it uses less digits than its factorization.

128977409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9568 (or 9557 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 128977409 is about 11356.8221347347. The cubic root of 128977409 is about 505.2479375919.

The spelling of 128977409 in words is "one hundred twenty-eight million, nine hundred seventy-seven thousand, four hundred nine".