166505505651 has 24 divisors (see below), whose sum is σ = 245652825600. Its totient is φ = 108629646576.

The previous prime is 166505505641. The next prime is 166505505671. The reversal of 166505505651 is 156505505661.

It is not a de Polignac number, because 166505505651 - 2⁹ = 166505505139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 166505505597 and 166505505606.

It is not an unprimeable number, because it can be changed into a prime (166505505631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5171200 + ... + 5203298.

It is an arithmetic number, because the mean of its divisors is an integer number (10235534400).

Almost surely, 2^166505505651 is an apocalyptic number.

166505505651 is a deficient number, since it is larger than the sum of its proper divisors (79147319949).

166505505651 is a wasteful number, since it uses less digits than its factorization.

166505505651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44415 (or 44412 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 45.

The spelling of 166505505651 in words is "one hundred sixty-six billion, five hundred five million, five hundred five thousand, six hundred fifty-one".