1661065561653 has 8 divisors (see below), whose sum is σ = 2311047738048. Its totient is φ = 1059230213184.

The previous prime is 1661065561627. The next prime is 1661065561663. The reversal of 1661065561653 is 3561655601661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1661065561653 - 2¹³ = 1661065553461 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1661065561596 and 1661065561605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661065561613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12036706900 + ... + 12036707037.

It is an arithmetic number, because the mean of its divisors is an integer number (288880967256).

Almost surely, 2^{1661065561653} is an apocalyptic number.

It is an amenable number.

1661065561653 is a deficient number, since it is larger than the sum of its proper divisors (649982176395).

1661065561653 is a wasteful number, since it uses less digits than its factorization.

1661065561653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24073413963.

The product of its (nonzero) digits is 2916000, while the sum is 51.

The spelling of 1661065561653 in words is "one trillion, six hundred sixty-one billion, sixty-five million, five hundred sixty-one thousand, six hundred fifty-three".