997543509409 has 2 divisors, whose sum is σ = 997543509410. Its totient is φ = 997543509408.

The previous prime is 997543509341. The next prime is 997543509427. The reversal of 997543509409 is 904905345799.

It is a happy number.

997543509409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 764015846400 + 233527663009 = 874080^2 + 483247^2 .

It is a cyclic number.

It is not a de Polignac number, because 997543509409 - 2¹⁵ = 997543476641 is a prime.

It is not a weakly prime, because it can be changed into another prime (997543509509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498771754704 + 498771754705.

It is an arithmetic number, because the mean of its divisors is an integer number (498771754705).

Almost surely, 2^997543509409 is an apocalyptic number.

It is an amenable number.

997543509409 is a deficient number, since it is larger than the sum of its proper divisors (1).

997543509409 is an equidigital number, since it uses as much as digits as its factorization.

997543509409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55112400, while the sum is 64.

The spelling of 997543509409 in words is "nine hundred ninety-seven billion, five hundred forty-three million, five hundred nine thousand, four hundred nine".