16660561977 has 16 divisors (see below), whose sum is σ = 25981384000. Its totient is φ = 10522459872.

The previous prime is 16660561961. The next prime is 16660561999. The reversal of 16660561977 is 77916506661.

It is not a de Polignac number, because 16660561977 - 2⁴ = 16660561961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16660561937) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16237852 + ... + 16238877.

It is an arithmetic number, because the mean of its divisors is an integer number (1623836500).

Almost surely, 2^16660561977 is an apocalyptic number.

It is an amenable number.

16660561977 is a deficient number, since it is larger than the sum of its proper divisors (9320822023).

16660561977 is a wasteful number, since it uses less digits than its factorization.

16660561977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32476757 (or 32476751 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The spelling of 16660561977 in words is "sixteen billion, six hundred sixty million, five hundred sixty-one thousand, nine hundred seventy-seven".