991384138453 has 2 divisors, whose sum is σ = 991384138454. Its totient is φ = 991384138452.

The previous prime is 991384138319. The next prime is 991384138517. The reversal of 991384138453 is 354831483199.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 693958973764 + 297425164689 = 833042^2 + 545367^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991384138453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991384139453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495692069226 + 495692069227.

It is an arithmetic number, because the mean of its divisors is an integer number (495692069227).

Almost surely, 2^991384138453 is an apocalyptic number.

It is an amenable number.

991384138453 is a deficient number, since it is larger than the sum of its proper divisors (1).

991384138453 is an equidigital number, since it uses as much as digits as its factorization.

991384138453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11197440, while the sum is 58.

The spelling of 991384138453 in words is "nine hundred ninety-one billion, three hundred eighty-four million, one hundred thirty-eight thousand, four hundred fifty-three".