128401277 has 2 divisors, whose sum is σ = 128401278. Its totient is φ = 128401276.

The previous prime is 128401267. The next prime is 128401283. The reversal of 128401277 is 772104821.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112232836 + 16168441 = 10594^2 + 4021^2 .

It is an emirp because it is prime and its reverse (772104821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128401277 - 2⁴ = 128401261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128401267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64200638 + 64200639.

It is an arithmetic number, because the mean of its divisors is an integer number (64200639).

Almost surely, 2^128401277 is an apocalyptic number.

It is an amenable number.

128401277 is a deficient number, since it is larger than the sum of its proper divisors (1).

128401277 is an equidigital number, since it uses as much as digits as its factorization.

128401277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 128401277 is about 11331.4287272171. The cubic root of 128401277 is about 504.4945136382.

The spelling of 128401277 in words is "one hundred twenty-eight million, four hundred one thousand, two hundred seventy-seven".