161651651000666 has 16 divisors (see below), whose sum is σ = 270253534181760. Its totient is φ = 72067609114560.

The previous prime is 161651651000633. The next prime is 161651651000677. The reversal of 161651651000666 is 666000156156161.

It is a super-3 number, since 3×161651651000666³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125117376290 + ... + 125117377581.

It is an arithmetic number, because the mean of its divisors is an integer number (16890845886360).

Almost surely, 2^{161651651000666} is an apocalyptic number.

161651651000666 is a deficient number, since it is larger than the sum of its proper divisors (108601883181094).

161651651000666 is a wasteful number, since it uses less digits than its factorization.

161651651000666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250234753909.

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

The spelling of 161651651000666 in words is "one hundred sixty-one trillion, six hundred fifty-one billion, six hundred fifty-one million, six hundred sixty-six", and thus it is an aban number.