1866826666839 has 4 divisors (see below), whose sum is σ = 2489102222456. Its totient is φ = 1244551111224.

The previous prime is 1866826666813. The next prime is 1866826666849. The reversal of 1866826666839 is 9386666286681.

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

It is not a de Polignac number, because 1866826666839 - 2⁸ = 1866826666583 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 (1866826666849) 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, 311137777804 + ... + 311137777809.

It is an arithmetic number, because the mean of its divisors is an integer number (622275555614).

Almost surely, 2^{1866826666839} is an apocalyptic number.

1866826666839 is a deficient number, since it is larger than the sum of its proper divisors (622275555617).

1866826666839 is an equidigital number, since it uses as much as digits as its factorization.

1866826666839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622275555616.

The product of its digits is 1289945088, while the sum is 75.

The spelling of 1866826666839 in words is "one trillion, eight hundred sixty-six billion, eight hundred twenty-six million, six hundred sixty-six thousand, eight hundred thirty-nine".