128277109 has 4 divisors (see below), whose sum is σ = 128375104. Its totient is φ = 128179116.

The previous prime is 128277089. The next prime is 128277137. The reversal of 128277109 is 901772821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128277109 - 2⁵ = 128277077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128277139) 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, 47007 + ... + 49660.

It is an arithmetic number, because the mean of its divisors is an integer number (32093776).

Almost surely, 2^128277109 is an apocalyptic number.

It is an amenable number.

128277109 is a deficient number, since it is larger than the sum of its proper divisors (97995).

128277109 is an equidigital number, since it uses as much as digits as its factorization.

128277109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97994.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 128277109 is about 11325.9484812531. The cubic root of 128277109 is about 504.3318405990.

The spelling of 128277109 in words is "one hundred twenty-eight million, two hundred seventy-seven thousand, one hundred nine".