1111155491 has 2 divisors, whose sum is σ = 1111155492. Its totient is φ = 1111155490.

The previous prime is 1111155469. The next prime is 1111155499. The reversal of 1111155491 is 1945511111.

It is a strong prime.

It is an emirp because it is prime and its reverse (1945511111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1111155491 - 2³⁰ = 37413667 is a prime.

It is not a weakly prime, because it can be changed into another prime (1111155499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555577745 + 555577746.

It is an arithmetic number, because the mean of its divisors is an integer number (555577746).

Almost surely, 2^1111155491 is an apocalyptic number.

1111155491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111155491 is an equidigital number, since it uses as much as digits as its factorization.

1111155491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 900, while the sum is 29.

The square root of 1111155491 is about 33333.9990250195. Note that the first 3 decimals coincide. The cubic root of 1111155491 is about 1035.7579583310.

The spelling of 1111155491 in words is "one billion, one hundred eleven million, one hundred fifty-five thousand, four hundred ninety-one".