97144387981 has 2 divisors, whose sum is σ = 97144387982. Its totient is φ = 97144387980.

The previous prime is 97144387939. The next prime is 97144387999. The reversal of 97144387981 is 18978344179.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79585487881 + 17558900100 = 282109^2 + 132510^2 .

It is a cyclic number.

It is not a de Polignac number, because 97144387981 - 2⁹ = 97144387469 is a prime.

It is a super-2 number, since 2×97144387981² (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 (97144387931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48572193990 + 48572193991.

It is an arithmetic number, because the mean of its divisors is an integer number (48572193991).

Almost surely, 2^97144387981 is an apocalyptic number.

It is an amenable number.

97144387981 is a deficient number, since it is larger than the sum of its proper divisors (1).

97144387981 is an equidigital number, since it uses as much as digits as its factorization.

97144387981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12192768, while the sum is 61.

The spelling of 97144387981 in words is "ninety-seven billion, one hundred forty-four million, three hundred eighty-seven thousand, nine hundred eighty-one".