1816973761 has 2 divisors, whose sum is σ = 1816973762. Its totient is φ = 1816973760.

The previous prime is 1816973759. The next prime is 1816973773. The reversal of 1816973761 is 1673796181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1772831025 + 44142736 = 42105^2 + 6644^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816973761 - 2¹ = 1816973759 is a prime.

Together with 1816973759, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1816976761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 908486880 + 908486881.

It is an arithmetic number, because the mean of its divisors is an integer number (908486881).

Almost surely, 2^1816973761 is an apocalyptic number.

It is an amenable number.

1816973761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1816973761 is an equidigital number, since it uses as much as digits as its factorization.

1816973761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 49.

The square root of 1816973761 is about 42625.9751911906. The cubic root of 1816973761 is about 1220.2520667464.

The spelling of 1816973761 in words is "one billion, eight hundred sixteen million, nine hundred seventy-three thousand, seven hundred sixty-one".