128582021 has 2 divisors, whose sum is σ = 128582022. Its totient is φ = 128582020.

The previous prime is 128582011. The next prime is 128582057. The reversal of 128582021 is 120285821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80820100 + 47761921 = 8990^2 + 6911^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128582021 is a prime.

It is a super-2 number, since 2×128582021² = 33066672248888882, which contains 22 as substring.

It is a Sophie Germain 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 (128582011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64291010 + 64291011.

It is an arithmetic number, because the mean of its divisors is an integer number (64291011).

Almost surely, 2^128582021 is an apocalyptic number.

It is an amenable number.

128582021 is a deficient number, since it is larger than the sum of its proper divisors (1).

128582021 is an equidigital number, since it uses as much as digits as its factorization.

128582021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 128582021 is about 11339.4012628533. The cubic root of 128582021 is about 504.7311198120.

The spelling of 128582021 in words is "one hundred twenty-eight million, five hundred eighty-two thousand, twenty-one".