128023702421 has 2 divisors, whose sum is σ = 128023702422. Its totient is φ = 128023702420.

The previous prime is 128023702409. The next prime is 128023702451. The reversal of 128023702421 is 124207320821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83934201796 + 44089500625 = 289714^2 + 209975^2 .

It is a cyclic number.

It is not a de Polignac number, because 128023702421 - 2³⁴ = 110843833237 is a prime.

It is a super-2 number, since 2×128023702421² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128023702451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64011851210 + 64011851211.

It is an arithmetic number, because the mean of its divisors is an integer number (64011851211).

Almost surely, 2^128023702421 is an apocalyptic number.

It is an amenable number.

128023702421 is a deficient number, since it is larger than the sum of its proper divisors (1).

128023702421 is an equidigital number, since it uses as much as digits as its factorization.

128023702421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 32.

The spelling of 128023702421 in words is "one hundred twenty-eight billion, twenty-three million, seven hundred two thousand, four hundred twenty-one".