1819851641 has 2 divisors, whose sum is σ = 1819851642. Its totient is φ = 1819851640.

The previous prime is 1819851601. The next prime is 1819851661. The reversal of 1819851641 is 1461589181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 984641641 + 835210000 = 31379^2 + 28900^2 .

It is a cyclic number.

It is not a de Polignac number, because 1819851641 - 2³⁰ = 746109817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1819851592 and 1819851601.

It is not a weakly prime, because it can be changed into another prime (1819851601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909925820 + 909925821.

It is an arithmetic number, because the mean of its divisors is an integer number (909925821).

Almost surely, 2^1819851641 is an apocalyptic number.

It is an amenable number.

1819851641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1819851641 is an equidigital number, since it uses as much as digits as its factorization.

1819851641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 44.

The square root of 1819851641 is about 42659.7191856674. The cubic root of 1819851641 is about 1220.8959737853.

The spelling of 1819851641 in words is "one billion, eight hundred nineteen million, eight hundred fifty-one thousand, six hundred forty-one".