1121785181 has 16 divisors (see below), whose sum is σ = 1253009088. Its totient is φ = 995683200.

The previous prime is 1121785157. The next prime is 1121785199. The reversal of 1121785181 is 1815871211.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1121785181 is a prime.

It is a super-2 number, since 2×1121785181² = 2516803984622405522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121785081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85826 + ... + 98028.

It is an arithmetic number, because the mean of its divisors is an integer number (78313068).

Almost surely, 2^1121785181 is an apocalyptic number.

1121785181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1121785181 is a deficient number, since it is larger than the sum of its proper divisors (131223907).

1121785181 is a wasteful number, since it uses less digits than its factorization.

1121785181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12412.

The product of its digits is 4480, while the sum is 35.

The square root of 1121785181 is about 33493.0616844743. The cubic root of 1121785181 is about 1039.0502859194.

The spelling of 1121785181 in words is "one billion, one hundred twenty-one million, seven hundred eighty-five thousand, one hundred eighty-one".