55039969691981 has 2 divisors, whose sum is σ = 55039969691982. Its totient is φ = 55039969691980.

The previous prime is 55039969691963. The next prime is 55039969692053. The reversal of 55039969691981 is 18919696993055.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48022058742025 + 7017910949956 = 6929795^2 + 2649134^2 .

It is a cyclic number.

It is not a de Polignac number, because 55039969691981 - 2²⁶ = 55039902583117 is a prime.

It is a super-2 number, since 2×55039969691981² (a number of 28 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 55039969691896 and 55039969691905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55039969691921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27519984845990 + 27519984845991.

It is an arithmetic number, because the mean of its divisors is an integer number (27519984845991).

Almost surely, 2^{55039969691981} is an apocalyptic number.

It is an amenable number.

55039969691981 is a deficient number, since it is larger than the sum of its proper divisors (1).

55039969691981 is an equidigital number, since it uses as much as digits as its factorization.

55039969691981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1275458400, while the sum is 80.

The spelling of 55039969691981 in words is "fifty-five trillion, thirty-nine billion, nine hundred sixty-nine million, six hundred ninety-one thousand, nine hundred eighty-one".