1809437323778 has 54 divisors (see below), whose sum is σ = 3354350569371. Its totient is φ = 729765759744.

The previous prime is 1809437323777. The next prime is 1809437323781. The reversal of 1809437323778 is 8773237349081.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 572054733649 + 1237382590129 = 756343^2 + 1112377^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=951167.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1809437323778.

It is not an unprimeable number, because it can be changed into a prime (1809437323777) 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 in 26 ways as a sum of consecutive naturals, for example, 226373750 + ... + 226381742.

Almost surely, 2^{1809437323778} is an apocalyptic number.

1809437323778 is a deficient number, since it is larger than the sum of its proper divisors (1544913245593).

1809437323778 is an frugal number, since it uses more digits than its factorization.

1809437323778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16036 (or 8019 counting only the distinct ones).

The product of its (nonzero) digits is 42674688, while the sum is 62.

The spelling of 1809437323778 in words is "one trillion, eight hundred nine billion, four hundred thirty-seven million, three hundred twenty-three thousand, seven hundred seventy-eight".