128532421 has 2 divisors, whose sum is σ = 128532422. Its totient is φ = 128532420.

The previous prime is 128532409. The next prime is 128532431. The reversal of 128532421 is 124235821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84456100 + 44076321 = 9190^2 + 6639^2 .

It is a cyclic number.

It is not a de Polignac number, because 128532421 - 2¹³ = 128524229 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128532421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128532431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64266210 + 64266211.

It is an arithmetic number, because the mean of its divisors is an integer number (64266211).

Almost surely, 2^128532421 is an apocalyptic number.

It is an amenable number.

128532421 is a deficient number, since it is larger than the sum of its proper divisors (1).

128532421 is an equidigital number, since it uses as much as digits as its factorization.

128532421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 28.

The square root of 128532421 is about 11337.2139875721. The cubic root of 128532421 is about 504.6662121288. Note that the first 3 decimals are identical.

The spelling of 128532421 in words is "one hundred twenty-eight million, five hundred thirty-two thousand, four hundred twenty-one".