128396779 has 8 divisors (see below), whose sum is σ = 146808288. Its totient is φ = 110002560.

The previous prime is 128396759. The next prime is 128396837. The reversal of 128396779 is 977693821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128396779 - 2¹⁵ = 128364011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128396759) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23889 + ... + 28765.

It is an arithmetic number, because the mean of its divisors is an integer number (18351036).

Almost surely, 2^128396779 is an apocalyptic number.

128396779 is a deficient number, since it is larger than the sum of its proper divisors (18411509).

128396779 is an equidigital number, since it uses as much as digits as its factorization.

128396779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8645.

The product of its digits is 1143072, while the sum is 52.

The square root of 128396779 is about 11331.2302509480. The cubic root of 128396779 is about 504.4886226199.

The spelling of 128396779 in words is "one hundred twenty-eight million, three hundred ninety-six thousand, seven hundred seventy-nine".