1661320085733 has 48 divisors (see below), whose sum is σ = 3061391663616. Its totient is φ = 842953093920.

The previous prime is 1661320085707. The next prime is 1661320085741. The reversal of 1661320085733 is 3375800231661.

1661320085733 is a `hidden beast` number, since 1 + 6 + 613 + 20 + 0 + 8 + 5 + 7 + 3 + 3 = 666.

It is not a de Polignac number, because 1661320085733 - 2¹² = 1661320081637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661320085773) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27845635 + ... + 27905232.

It is an arithmetic number, because the mean of its divisors is an integer number (63778992992).

Almost surely, 2^{1661320085733} is an apocalyptic number.

It is an amenable number.

1661320085733 is a deficient number, since it is larger than the sum of its proper divisors (1400071577883).

1661320085733 is a wasteful number, since it uses less digits than its factorization.

1661320085733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55750934 (or 55750931 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 1661320085733 in words is "one trillion, six hundred sixty-one billion, three hundred twenty million, eighty-five thousand, seven hundred thirty-three".