166677755561 has 16 divisors (see below), whose sum is σ = 168510347136. Its totient is φ = 164855154816.

The previous prime is 166677755533. The next prime is 166677755591. The reversal of 166677755561 is 165557776661.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166677755561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166677755494 and 166677755503.

It is not an unprimeable number, because it can be changed into a prime (166677755591) 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, 87402170 + ... + 87404076.

It is an arithmetic number, because the mean of its divisors is an integer number (10531896696).

Almost surely, 2^166677755561 is an apocalyptic number.

It is an amenable number.

166677755561 is a deficient number, since it is larger than the sum of its proper divisors (1832591575).

166677755561 is a wasteful number, since it uses less digits than its factorization.

166677755561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4048.

The product of its digits is 55566000, while the sum is 62.

The spelling of 166677755561 in words is "one hundred sixty-six billion, six hundred seventy-seven million, seven hundred fifty-five thousand, five hundred sixty-one".