128211701 has 2 divisors, whose sum is σ = 128211702. Its totient is φ = 128211700.

The previous prime is 128211689. The next prime is 128211703. The reversal of 128211701 is 107112821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80532676 + 47679025 = 8974^2 + 6905^2 .

It is an emirp because it is prime and its reverse (107112821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128211701 - 2²⁶ = 61102837 is a prime.

It is a Sophie Germain prime.

Together with 128211703, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128211703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64105850 + 64105851.

It is an arithmetic number, because the mean of its divisors is an integer number (64105851).

Almost surely, 2^128211701 is an apocalyptic number.

It is an amenable number.

128211701 is a deficient number, since it is larger than the sum of its proper divisors (1).

128211701 is an equidigital number, since it uses as much as digits as its factorization.

128211701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 23.

The square root of 128211701 is about 11323.0605844886. The cubic root of 128211701 is about 504.2461070762.

The spelling of 128211701 in words is "one hundred twenty-eight million, two hundred eleven thousand, seven hundred one".