11989191551849 has 2 divisors, whose sum is σ = 11989191551850. Its totient is φ = 11989191551848.

The previous prime is 11989191551693. The next prime is 11989191551881. The reversal of 11989191551849 is 94815519198911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6726594970624 + 5262596581225 = 2593568^2 + 2294035^2 .

It is a cyclic number.

It is not a de Polignac number, because 11989191551849 - 2⁸ = 11989191551593 is a prime.

It is not a weakly prime, because it can be changed into another prime (11989191551549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5994595775924 + 5994595775925.

It is an arithmetic number, because the mean of its divisors is an integer number (5994595775925).

Almost surely, 2^{11989191551849} is an apocalyptic number.

It is an amenable number.

11989191551849 is a deficient number, since it is larger than the sum of its proper divisors (1).

11989191551849 is an equidigital number, since it uses as much as digits as its factorization.

11989191551849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41990400, while the sum is 71.

The spelling of 11989191551849 in words is "eleven trillion, nine hundred eighty-nine billion, one hundred ninety-one million, five hundred fifty-one thousand, eight hundred forty-nine".