1798154398549 has 2 divisors, whose sum is σ = 1798154398550. Its totient is φ = 1798154398548.

The previous prime is 1798154398543. The next prime is 1798154398589. The reversal of 1798154398549 is 9458934518971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1305831852900 + 492322545649 = 1142730^2 + 701657^2 .

It is a cyclic number.

It is not a de Polignac number, because 1798154398549 - 2³⁵ = 1763794660181 is a prime.

It is a super-2 number, since 2×1798154398549² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1798154398543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 899077199274 + 899077199275.

It is an arithmetic number, because the mean of its divisors is an integer number (899077199275).

Almost surely, 2^{1798154398549} is an apocalyptic number.

It is an amenable number.

1798154398549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1798154398549 is an equidigital number, since it uses as much as digits as its factorization.

1798154398549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 391910400, while the sum is 73.

The spelling of 1798154398549 in words is "one trillion, seven hundred ninety-eight billion, one hundred fifty-four million, three hundred ninety-eight thousand, five hundred forty-nine".