1445197981 has 2 divisors, whose sum is σ = 1445197982. Its totient is φ = 1445197980.

The previous prime is 1445197913. The next prime is 1445197987. The reversal of 1445197981 is 1897915441.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1437547225 + 7650756 = 37915^2 + 2766^2 .

It is an emirp because it is prime and its reverse (1897915441) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1445197981 - 2²¹ = 1443100829 is a prime.

It is a super-2 number, since 2×1445197981² = 4177194408572952722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1445197987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 722598990 + 722598991.

It is an arithmetic number, because the mean of its divisors is an integer number (722598991).

Almost surely, 2^1445197981 is an apocalyptic number.

It is an amenable number.

1445197981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1445197981 is an equidigital number, since it uses as much as digits as its factorization.

1445197981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 49.

The square root of 1445197981 is about 38015.7596399178. The cubic root of 1445197981 is about 1130.6003495344.

The spelling of 1445197981 in words is "one billion, four hundred forty-five million, one hundred ninety-seven thousand, nine hundred eighty-one".