1121977991 has 2 divisors, whose sum is σ = 1121977992. Its totient is φ = 1121977990.

The previous prime is 1121977957. The next prime is 1121977999. The reversal of 1121977991 is 1997791211.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1121977991 - 2¹⁰ = 1121976967 is a prime.

It is a super-2 number, since 2×1121977991² = 2517669224576792162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1121977999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560988995 + 560988996.

It is an arithmetic number, because the mean of its divisors is an integer number (560988996).

Almost surely, 2^1121977991 is an apocalyptic number.

1121977991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121977991 is an equidigital number, since it uses as much as digits as its factorization.

1121977991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71442, while the sum is 47.

The square root of 1121977991 is about 33495.9399181453. The cubic root of 1121977991 is about 1039.1098124111.

The spelling of 1121977991 in words is "one billion, one hundred twenty-one million, nine hundred seventy-seven thousand, nine hundred ninety-one".