20128953752681 has 2 divisors, whose sum is σ = 20128953752682. Its totient is φ = 20128953752680.

The previous prime is 20128953752653. The next prime is 20128953752701. The reversal of 20128953752681 is 18625735982102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11154825133456 + 8974128619225 = 3339884^2 + 2995685^2 .

It is a cyclic number.

It is not a de Polignac number, because 20128953752681 - 2³⁰ = 20127880010857 is a prime.

It is a super-2 number, since 2×20128953752681² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20128953752681.

It is not a weakly prime, because it can be changed into another prime (20128953752641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10064476876340 + 10064476876341.

It is an arithmetic number, because the mean of its divisors is an integer number (10064476876341).

Almost surely, 2^{20128953752681} is an apocalyptic number.

It is an amenable number.

20128953752681 is a deficient number, since it is larger than the sum of its proper divisors (1).

20128953752681 is an equidigital number, since it uses as much as digits as its factorization.

20128953752681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14515200, while the sum is 59.

The spelling of 20128953752681 in words is "twenty trillion, one hundred twenty-eight billion, nine hundred fifty-three million, seven hundred fifty-two thousand, six hundred eighty-one".