243115554491 has 2 divisors, whose sum is σ = 243115554492. Its totient is φ = 243115554490.

The previous prime is 243115554463. The next prime is 243115554509. The reversal of 243115554491 is 194455511342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243115554491 is a prime.

It is not a weakly prime, because it can be changed into another prime (243115514491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121557777245 + 121557777246.

It is an arithmetic number, because the mean of its divisors is an integer number (121557777246).

Almost surely, 2^243115554491 is an apocalyptic number.

243115554491 is a deficient number, since it is larger than the sum of its proper divisors (1).

243115554491 is an equidigital number, since it uses as much as digits as its factorization.

243115554491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 44.

The spelling of 243115554491 in words is "two hundred forty-three billion, one hundred fifteen million, five hundred fifty-four thousand, four hundred ninety-one".