128877979 has 2 divisors, whose sum is σ = 128877980. Its totient is φ = 128877978.

The previous prime is 128877977. The next prime is 128877989. The reversal of 128877979 is 979778821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128877979 - 2¹ = 128877977 is a prime.

It is a super-2 number, since 2×128877979² = 33219066942248882, which contains 22 as substring.

Together with 128877977, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (128877971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64438989 + 64438990.

It is an arithmetic number, because the mean of its divisors is an integer number (64438990).

Almost surely, 2^128877979 is an apocalyptic number.

128877979 is a deficient number, since it is larger than the sum of its proper divisors (1).

128877979 is an equidigital number, since it uses as much as digits as its factorization.

128877979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3556224, while the sum is 58.

The square root of 128877979 is about 11352.4437457316. The cubic root of 128877979 is about 505.1180706182.

The spelling of 128877979 in words is "one hundred twenty-eight million, eight hundred seventy-seven thousand, nine hundred seventy-nine".