11865034781 has 4 divisors (see below), whose sum is σ = 11865287292. Its totient is φ = 11864782272.

The previous prime is 11865034729. The next prime is 11865034801. The reversal of 11865034781 is 18743056811.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 652342681 + 11212692100 = 25541^2 + 105890^2 .

It is a cyclic number.

It is not a de Polignac number, because 11865034781 - 2⁶ = 11865034717 is a prime.

It is a super-2 number, since 2×11865034781² (a number of 21 digits) 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 (11865034381) 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, 32630 + ... + 157463.

It is an arithmetic number, because the mean of its divisors is an integer number (2966321823).

Almost surely, 2^11865034781 is an apocalyptic number.

It is an amenable number.

11865034781 is a deficient number, since it is larger than the sum of its proper divisors (252511).

11865034781 is an equidigital number, since it uses as much as digits as its factorization.

11865034781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252510.

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 11865034781 in words is "eleven billion, eight hundred sixty-five million, thirty-four thousand, seven hundred eighty-one".