168756561 has 32 divisors (see below), whose sum is σ = 257523200. Its totient is φ = 109175040.

The previous prime is 168756551. The next prime is 168756629. The reversal of 168756561 is 165657861.

168756561 is a `hidden beast` number, since 1 + 6 + 87 + 5 + 6 + 561 = 666.

It is not a de Polignac number, because 168756561 - 2¹¹ = 168754513 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

Its product of digits (302400) is a multiple of the sum of its prime divisors (1440).

It is not an unprimeable number, because it can be changed into a prime (168756551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129465 + ... + 130761.

It is an arithmetic number, because the mean of its divisors is an integer number (8047600).

Almost surely, 2^168756561 is an apocalyptic number.

It is an amenable number.

168756561 is a deficient number, since it is larger than the sum of its proper divisors (88766639).

168756561 is a wasteful number, since it uses less digits than its factorization.

168756561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1446 (or 1440 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 168756561 is about 12990.6335873198. The cubic root of 168756561 is about 552.6118864605.

It can be divided in two parts, 16875 and 6561, that added together give a triangular number (23436 = T₂₁₆).

The spelling of 168756561 in words is "one hundred sixty-eight million, seven hundred fifty-six thousand, five hundred sixty-one".