128777461 has 2 divisors, whose sum is σ = 128777462. Its totient is φ = 128777460.

The previous prime is 128777449. The next prime is 128777479. The reversal of 128777461 is 164777821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114383025 + 14394436 = 10695^2 + 3794^2 .

It is a cyclic number.

It is not a de Polignac number, because 128777461 - 2¹³ = 128769269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128777861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64388730 + 64388731.

It is an arithmetic number, because the mean of its divisors is an integer number (64388731).

Almost surely, 2^128777461 is an apocalyptic number.

It is an amenable number.

128777461 is a deficient number, since it is larger than the sum of its proper divisors (1).

128777461 is an equidigital number, since it uses as much as digits as its factorization.

128777461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 131712, while the sum is 43.

The square root of 128777461 is about 11348.0157296331. The cubic root of 128777461 is about 504.9867146784.

The spelling of 128777461 in words is "one hundred twenty-eight million, seven hundred seventy-seven thousand, four hundred sixty-one".