720001109981 has 2 divisors, whose sum is σ = 720001109982. Its totient is φ = 720001109980.

The previous prime is 720001109969. The next prime is 720001110061. The reversal of 720001109981 is 189901100027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 546503869081 + 173497240900 = 739259^2 + 416530^2 .

It is a cyclic number.

It is not a de Polignac number, because 720001109981 - 2³⁸ = 445123203037 is a prime.

It is a super-2 number, since 2×720001109981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720001109951) 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, 360000554990 + 360000554991.

It is an arithmetic number, because the mean of its divisors is an integer number (360000554991).

Almost surely, 2^720001109981 is an apocalyptic number.

It is an amenable number.

720001109981 is a deficient number, since it is larger than the sum of its proper divisors (1).

720001109981 is an equidigital number, since it uses as much as digits as its factorization.

720001109981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 38.

The spelling of 720001109981 in words is "seven hundred twenty billion, one million, one hundred nine thousand, nine hundred eighty-one".