1998403628761 has 12 divisors (see below), whose sum is σ = 2174649045660. Its totient is φ = 1834976061440.

The previous prime is 1998403628731. The next prime is 1998403628777. The reversal of 1998403628761 is 1678263048991.

It can be written as a sum of positive squares in 6 ways, for example, as 8103420361 + 1990300208400 = 90019^2 + 1410780^2 .

It is not a de Polignac number, because 1998403628761 - 2¹⁷ = 1998403497689 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1998403628693 and 1998403628702.

It is not an unprimeable number, because it can be changed into a prime (1998403628731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84316096 + ... + 84339793.

It is an arithmetic number, because the mean of its divisors is an integer number (181220753805).

Almost surely, 2^{1998403628761} is an apocalyptic number.

It is an amenable number.

1998403628761 is a deficient number, since it is larger than the sum of its proper divisors (176245416899).

1998403628761 is a wasteful number, since it uses less digits than its factorization.

1998403628761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168655964 (or 168655947 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 64.

The spelling of 1998403628761 in words is "one trillion, nine hundred ninety-eight billion, four hundred three million, six hundred twenty-eight thousand, seven hundred sixty-one".