11051800781 has 4 divisors (see below), whose sum is σ = 12630629472. Its totient is φ = 9472972092.

The previous prime is 11051800777. The next prime is 11051800801. The reversal of 11051800781 is 18700815011.

11051800781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18700815011 = 223 ⋅83860157.

It is a cyclic number.

It is not a de Polignac number, because 11051800781 - 2² = 11051800777 is a prime.

It is a super-2 number, since 2×11051800781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11051800751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 789414335 + ... + 789414348.

It is an arithmetic number, because the mean of its divisors is an integer number (3157657368).

Almost surely, 2^11051800781 is an apocalyptic number.

It is an amenable number.

11051800781 is a deficient number, since it is larger than the sum of its proper divisors (1578828691).

11051800781 is an equidigital number, since it uses as much as digits as its factorization.

11051800781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578828690.

The product of its (nonzero) digits is 2240, while the sum is 32.

The spelling of 11051800781 in words is "eleven billion, fifty-one million, eight hundred thousand, seven hundred eighty-one".