5665267801981 has 2 divisors, whose sum is σ = 5665267801982. Its totient is φ = 5665267801980.

The previous prime is 5665267801951. The next prime is 5665267802069. The reversal of 5665267801981 is 1891087625665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5616378612100 + 48889189881 = 2369890^2 + 221109^2 .

It is a cyclic number.

It is not a de Polignac number, because 5665267801981 - 2²⁵ = 5665234247549 is a prime.

It is a super-2 number, since 2×5665267801981² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5665267801951) 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, 2832633900990 + 2832633900991.

It is an arithmetic number, because the mean of its divisors is an integer number (2832633900991).

Almost surely, 2^{5665267801981} is an apocalyptic number.

It is an amenable number.

5665267801981 is a deficient number, since it is larger than the sum of its proper divisors (1).

5665267801981 is an equidigital number, since it uses as much as digits as its factorization.

5665267801981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43545600, while the sum is 64.

The spelling of 5665267801981 in words is "five trillion, six hundred sixty-five billion, two hundred sixty-seven million, eight hundred one thousand, nine hundred eighty-one".