1661600666001 has 8 divisors (see below), whose sum is σ = 2216159252640. Its totient is φ = 1107387928352.

The previous prime is 1661600665993. The next prime is 1661600666021. The reversal of 1661600666001 is 1006660061661.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1661600666001 - 2³ = 1661600665993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661600666021) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 86451036 + ... + 86470253.

It is an arithmetic number, because the mean of its divisors is an integer number (277019906580).

Almost surely, 2^{1661600666001} is an apocalyptic number.

It is an amenable number.

1661600666001 is a deficient number, since it is larger than the sum of its proper divisors (554558586639).

1661600666001 is a wasteful number, since it uses less digits than its factorization.

1661600666001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172924495.

The product of its (nonzero) digits is 46656, while the sum is 39.

The spelling of 1661600666001 in words is "one trillion, six hundred sixty-one billion, six hundred million, six hundred sixty-six thousand, one".