1661326989648 has 40 divisors (see below), whose sum is σ = 4331871322848. Its totient is φ = 548600188032.

The previous prime is 1661326989631. The next prime is 1661326989683. The reversal of 1661326989648 is 8469896231661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161728411 + ... + 161738682.

Almost surely, 2^{1661326989648} is an apocalyptic number.

It is an amenable number.

1661326989648 is an abundant number, since it is smaller than the sum of its proper divisors (2670544333200).

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

1661326989648 is a wasteful number, since it uses less digits than its factorization.

1661326989648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323467211 (or 323467205 counting only the distinct ones).

The product of its digits is 161243136, while the sum is 69.

The spelling of 1661326989648 in words is "one trillion, six hundred sixty-one billion, three hundred twenty-six million, nine hundred eighty-nine thousand, six hundred forty-eight".