11550006781 has 4 divisors (see below), whose sum is σ = 11550243292. Its totient is φ = 11549770272.

The previous prime is 11550006779. The next prime is 11550006791. The reversal of 11550006781 is 18760005511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18760005511 = 13 ⋅1443077347.

It can be written as a sum of positive squares in 2 ways, for example, as 7350318756 + 4199688025 = 85734^2 + 64805^2 .

It is a cyclic number.

It is not a de Polignac number, because 11550006781 - 2¹ = 11550006779 is a prime.

It is a super-2 number, since 2×11550006781² (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 (11550006791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14880 + ... + 152713.

It is an arithmetic number, because the mean of its divisors is an integer number (2887560823).

Almost surely, 2^11550006781 is an apocalyptic number.

It is an amenable number.

11550006781 is a deficient number, since it is larger than the sum of its proper divisors (236511).

11550006781 is an equidigital number, since it uses as much as digits as its factorization.

11550006781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236510.

The product of its (nonzero) digits is 8400, while the sum is 34.

The spelling of 11550006781 in words is "eleven billion, five hundred fifty million, six thousand, seven hundred eighty-one".