1666800923 has 4 divisors (see below), whose sum is σ = 1676112840. Its totient is φ = 1657489008.

The previous prime is 1666800833. The next prime is 1666800943. The reversal of 1666800923 is 3290086661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3290086661 = 773 ⋅4256257.

It is a cyclic number.

It is not a de Polignac number, because 1666800923 - 2¹² = 1666796827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666800943) 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, 4655690 + ... + 4656047.

It is an arithmetic number, because the mean of its divisors is an integer number (419028210).

Almost surely, 2^1666800923 is an apocalyptic number.

1666800923 is a deficient number, since it is larger than the sum of its proper divisors (9311917).

1666800923 is an equidigital number, since it uses as much as digits as its factorization.

1666800923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9311916.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 1666800923 is about 40826.4733108310. The cubic root of 1666800923 is about 1185.6629363388.

The spelling of 1666800923 in words is "one billion, six hundred sixty-six million, eight hundred thousand, nine hundred twenty-three".