1665561510010 has 16 divisors (see below), whose sum is σ = 3010450600872. Its totient is φ = 663460185600.

The previous prime is 1665561509921. The next prime is 1665561510017. The reversal of 1665561510010 is 100151655661.

It can be written as a sum of positive squares in 4 ways, for example, as 1398407946849 + 267153563161 = 1182543^2 + 516869^2 .

It is not an unprimeable number, because it can be changed into a prime (1665561510017) 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, 345549771 + ... + 345554590.

Almost surely, 2^{1665561510010} is an apocalyptic number.

1665561510010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1665561510010 is a deficient number, since it is larger than the sum of its proper divisors (1344889090862).

1665561510010 is a wasteful number, since it uses less digits than its factorization.

1665561510010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691104609.

The product of its (nonzero) digits is 27000, while the sum is 37.

The spelling of 1665561510010 in words is "one trillion, six hundred sixty-five billion, five hundred sixty-one million, five hundred ten thousand, ten".