1661326352361 has 80 divisors (see below), whose sum is σ = 2688000915600. Its totient is φ = 1016492654592.

The previous prime is 1661326352341. The next prime is 1661326352383. The reversal of 1661326352361 is 1632536231661.

1661326352361 is a `hidden beast` number, since 1 + 6 + 6 + 1 + 3 + 2 + 63 + 523 + 61 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 8661838761 + 1652664513600 = 93069^2 + 1285560^2 .

It is not a de Polignac number, because 1661326352361 - 2⁶ = 1661326352297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661326352341) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 153977955 + ... + 153988743.

It is an arithmetic number, because the mean of its divisors is an integer number (33600011445).

Almost surely, 2^{1661326352361} is an apocalyptic number.

It is an amenable number.

1661326352361 is a deficient number, since it is larger than the sum of its proper divisors (1026674563239).

1661326352361 is a wasteful number, since it uses less digits than its factorization.

1661326352361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11640 (or 11631 counting only the distinct ones).

The product of its digits is 699840, while the sum is 45.

The spelling of 1661326352361 in words is "one trillion, six hundred sixty-one billion, three hundred twenty-six million, three hundred fifty-two thousand, three hundred sixty-one".