1820618088721 has 2 divisors, whose sum is σ = 1820618088722. Its totient is φ = 1820618088720.

The previous prime is 1820618088647. The next prime is 1820618088833. The reversal of 1820618088721 is 1278808160281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1717986918400 + 102631170321 = 1310720^2 + 320361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820618088721 - 2⁷ = 1820618088593 is a prime.

It is not a weakly prime, because it can be changed into another prime (1820612088721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910309044360 + 910309044361.

It is an arithmetic number, because the mean of its divisors is an integer number (910309044361).

Almost surely, 2^{1820618088721} is an apocalyptic number.

It is an amenable number.

1820618088721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820618088721 is an equidigital number, since it uses as much as digits as its factorization.

1820618088721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 688128, while the sum is 52.

The spelling of 1820618088721 in words is "one trillion, eight hundred twenty billion, six hundred eighteen million, eighty-eight thousand, seven hundred twenty-one".