1661516516606 has 4 divisors (see below), whose sum is σ = 2492274774912. Its totient is φ = 830758258302.

The previous prime is 1661516516521. The next prime is 1661516516677. The reversal of 1661516516606 is 6066156151661.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415379129150 + ... + 415379129153.

It is an arithmetic number, because the mean of its divisors is an integer number (623068693728).

Almost surely, 2^{1661516516606} is an apocalyptic number.

1661516516606 is a deficient number, since it is larger than the sum of its proper divisors (830758258306).

1661516516606 is an equidigital number, since it uses as much as digits as its factorization.

1661516516606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830758258305.

The product of its (nonzero) digits is 1166400, while the sum is 50.

The spelling of 1661516516606 in words is "one trillion, six hundred sixty-one billion, five hundred sixteen million, five hundred sixteen thousand, six hundred six".