1609009691904 has 180 divisors, whose sum is σ = 4876431660100. Its totient is φ = 527543746560.

The previous prime is 1609009691903. The next prime is 1609009691909. The reversal of 1609009691904 is 4091969009061.

It can be written as a sum of positive squares in 2 ways, for example, as 318150146304 + 1290859545600 = 564048^2 + 1136160^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1609009691903) 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 19 ways as a sum of consecutive naturals, for example, 628872 + ... + 1900920.

Almost surely, 2^{1609009691904} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1609009691904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2438215830050).

1609009691904 is an abundant number, since it is smaller than the sum of its proper divisors (3267421968196).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1609009691904 is an equidigital number, since it uses as much as digits as its factorization.

1609009691904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272138 (or 1272115 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 54.

The spelling of 1609009691904 in words is "one trillion, six hundred nine billion, nine million, six hundred ninety-one thousand, nine hundred four".