1665561050465 has 8 divisors (see below), whose sum is σ = 2152417357608. Its totient is φ = 1229952775680.

The previous prime is 1665561050443. The next prime is 1665561050471. The reversal of 1665561050465 is 5640501655661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 30108843361 + 1635452207104 = 173519^2 + 1278848^2 .

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

It is not a de Polignac number, because 1665561050465 - 2¹⁶ = 1665560984929 is a prime.

It is a super-2 number, since 2×1665561050465² (a number of 25 digits) contains 22 as substring.

It is a Duffinian 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, 12812008016 + ... + 12812008145.

It is an arithmetic number, because the mean of its divisors is an integer number (269052169701).

Almost surely, 2^{1665561050465} is an apocalyptic number.

It is an amenable number.

1665561050465 is a deficient number, since it is larger than the sum of its proper divisors (486856307143).

1665561050465 is a wasteful number, since it uses less digits than its factorization.

1665561050465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25624016179.

The product of its (nonzero) digits is 3240000, while the sum is 50.

The spelling of 1665561050465 in words is "one trillion, six hundred sixty-five billion, five hundred sixty-one million, fifty thousand, four hundred sixty-five".