1661506611101 has 8 divisors (see below), whose sum is σ = 1662844204800. Its totient is φ = 1660169274400.

The previous prime is 1661506611053. The next prime is 1661506611109. The reversal of 1661506611101 is 1011166051661.

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 1661506611101 - 2¹⁰ = 1661506610077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661506611109) 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, 14116985 + ... + 14234193.

It is an arithmetic number, because the mean of its divisors is an integer number (207855525600).

Almost surely, 2^{1661506611101} is an apocalyptic number.

It is an amenable number.

1661506611101 is a deficient number, since it is larger than the sum of its proper divisors (1337593699).

1661506611101 is a wasteful number, since it uses less digits than its factorization.

1661506611101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128499.

The product of its (nonzero) digits is 6480, while the sum is 35.

The spelling of 1661506611101 in words is "one trillion, six hundred sixty-one billion, five hundred six million, six hundred eleven thousand, one hundred one".