55555549991 has 2 divisors, whose sum is σ = 55555549992. Its totient is φ = 55555549990.

The previous prime is 55555549949. The next prime is 55555549997. The reversal of 55555549991 is 19994555555.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55555549991 - 2³⁰ = 54481808167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55555549997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27777774995 + 27777774996.

It is an arithmetic number, because the mean of its divisors is an integer number (27777774996).

Almost surely, 2^55555549991 is an apocalyptic number.

55555549991 is a deficient number, since it is larger than the sum of its proper divisors (1).

55555549991 is an equidigital number, since it uses as much as digits as its factorization.

55555549991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45562500, while the sum is 62.

The spelling of 55555549991 in words is "fifty-five billion, five hundred fifty-five million, five hundred forty-nine thousand, nine hundred ninety-one".