1665559520906 has 8 divisors (see below), whose sum is σ = 2498346154020. Its totient is φ = 832777469568.

The previous prime is 1665559520897. The next prime is 1665559520957. The reversal of 1665559520906 is 6090259555661.

It can be written as a sum of positive squares in 2 ways, for example, as 1664706355225 + 853165681 = 1290235^2 + 29209^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12551 + ... + 1825178.

Almost surely, 2^{1665559520906} is an apocalyptic number.

1665559520906 is a deficient number, since it is larger than the sum of its proper divisors (832786633114).

1665559520906 is a wasteful number, since it uses less digits than its factorization.

1665559520906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290888.

The product of its (nonzero) digits is 21870000, while the sum is 59.

The spelling of 1665559520906 in words is "one trillion, six hundred sixty-five billion, five hundred fifty-nine million, five hundred twenty thousand, nine hundred six".