11811819493 has 4 divisors (see below), whose sum is σ = 11814829740. Its totient is φ = 11808809248.

The previous prime is 11811819479. The next prime is 11811819563. The reversal of 11811819493 is 39491811811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39491811811 = 61 ⋅647406751.

It can be written as a sum of positive squares in 2 ways, for example, as 5812232644 + 5999586849 = 76238^2 + 77457^2 .

It is a cyclic number.

It is not a de Polignac number, because 11811819493 - 2²¹ = 11809722341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11811819463) 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, 1499230 + ... + 1507087.

It is an arithmetic number, because the mean of its divisors is an integer number (2953707435).

Almost surely, 2^11811819493 is an apocalyptic number.

It is an amenable number.

11811819493 is a deficient number, since it is larger than the sum of its proper divisors (3010247).

11811819493 is an equidigital number, since it uses as much as digits as its factorization.

11811819493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3010246.

The product of its digits is 62208, while the sum is 46.

The spelling of 11811819493 in words is "eleven billion, eight hundred eleven million, eight hundred nineteen thousand, four hundred ninety-three".