128520811 has 2 divisors, whose sum is σ = 128520812. Its totient is φ = 128520810.

The previous prime is 128520809. The next prime is 128520827. The reversal of 128520811 is 118025821.

It is a weak prime.

It is an emirp because it is prime and its reverse (118025821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128520811 - 2¹ = 128520809 is a prime.

Together with 128520809, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 128520811.

It is not a weakly prime, because it can be changed into another prime (128520871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64260405 + 64260406.

It is an arithmetic number, because the mean of its divisors is an integer number (64260406).

Almost surely, 2^128520811 is an apocalyptic number.

128520811 is a deficient number, since it is larger than the sum of its proper divisors (1).

128520811 is an equidigital number, since it uses as much as digits as its factorization.

128520811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1280, while the sum is 28.

The square root of 128520811 is about 11336.7019454513. The cubic root of 128520811 is about 504.6510166082.

The spelling of 128520811 in words is "one hundred twenty-eight million, five hundred twenty thousand, eight hundred eleven".