1815847849 has 2 divisors, whose sum is σ = 1815847850. Its totient is φ = 1815847848.

The previous prime is 1815847819. The next prime is 1815847871. The reversal of 1815847849 is 9487485181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1814760000 + 1087849 = 42600^2 + 1043^2 .

It is a cyclic number.

It is not a de Polignac number, because 1815847849 - 2¹³ = 1815839657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1815847849.

It is not a weakly prime, because it can be changed into another prime (1815847819) 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 as a sum of consecutive naturals, namely, 907923924 + 907923925.

It is an arithmetic number, because the mean of its divisors is an integer number (907923925).

Almost surely, 2^1815847849 is an apocalyptic number.

It is an amenable number.

1815847849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1815847849 is an equidigital number, since it uses as much as digits as its factorization.

1815847849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2580480, while the sum is 55.

The square root of 1815847849 is about 42612.7662678686. The cubic root of 1815847849 is about 1219.9999661829. Note that the first 4 decimals are identical.

The spelling of 1815847849 in words is "one billion, eight hundred fifteen million, eight hundred forty-seven thousand, eight hundred forty-nine".